Puma Punku: A Sixth-Century Stone Platform, H-Blocks Cut to Millimeter Tolerance, and an Andean Tradition That Knew What It Was Doing.

What Puma Punku is, in a paragraph.

Puma Punku (the name is Aymara; it translates approximately as "Door of the Puma") is a megalithic platform-and-temple complex forming the southwestern sector of the larger Tiwanaku archaeological zone in the La Paz Department of western Bolivia, near the southern shore of Lake Titicaca at an elevation of approximately 3,850 meters. The complex consists of an artificial earthen platform faced and capped with massive stone slabs, atop which once stood architectural structures whose specific configuration has been substantially reconstructed but not entirely. The component stones — principally red sandstone (locally available) and andesite (from quarries on the Copacabana Peninsula across the southern arm of Lake Titicaca, approximately 90 kilometers away by water and overland transport) — include some of the largest worked blocks in pre-Columbian American architecture. The largest documented block weighs an estimated 131 tons; the total mass of the platform's stone facing has been estimated at approximately 6 million kilograms. The most distinctive elements of Puma Punku are the so-called H-blocks — carved sandstone blocks with H-shaped (or, more accurately, square-stepped) profiles whose forms interlock with adjacent blocks in a modular manner, with cut tolerances that in the best-preserved examples approach millimeter precision. The mainstream radiocarbon dating, based on organic material recovered from sealed contexts within the platform substructure during the long sequence of professional excavations from Wendell Bennett in 1932 onward, places the principal construction phase at approximately 536–600 CE — the late Tiwanaku III / early Tiwanaku V cultural-chronological horizon. The construction is therefore contemporaneous with Byzantine Justinian and with the Late Antique Little Ice Age that affected much of the Northern Hemisphere. The mainstream archaeological consensus, developed across the work of Bennett (1932), Carlos Ponce Sanginés (1957–1972), Alan Kolata (1980s–2000s), and continuing teams, interprets Puma Punku as the product of organized labor by the Tiwanaku state polity, using stone-pounding techniques with hammerstones (no metal tools were available in the relevant period), inclined-plane and roller transport methods for moving the large blocks from the quarries, and a sophisticated mason tradition with antecedents in earlier Andean stoneworking. The site was substantially destroyed in the post-Tiwanaku period by a combination of stone-removal for later construction (colonial-era church-building in La Paz and modern-period infrastructure both drew on Tiwanaku stone), seismic events, and natural weathering; the surviving structure represents an estimated 10–20% of the original built mass. From the 1960s onward, Puma Punku has been a focal site for popular alien-construction claims, most prominently those of Erich von Däniken (Chariots of the Gods, 1968 and successor works) and Brien Foerster (multiple recent self-published and online works). These framings rest principally on the technical impressiveness of the joinery and the difficulty of imagining how non-metal-tool societies achieved it; they are not supported by the archaeological record, which provides positive evidence (stone-pounding workshop debris, partially-completed blocks showing the stone-pounding production sequence, ethnographic and experimental archaeological parallels in Andean stoneworking) for the conventional explanation. The genuine open questions about Puma Punku — the precise transport mechanism for the largest blocks across the 90-km Copacabana-quarry distance, the exact configuration of the architectural structures that once stood atop the platform, the social organization of the labor force, the reasons for the site's late-period abandonment — are technical archaeological questions that are the subject of continuing investigation rather than paranormal questions requiring exotic explanations.

The documented record.

The site and its setting

The Tiwanaku archaeological complex consists of several discrete components: the Akapana platform (a large stepped earthen platform with retaining walls), the Kalasasaya enclosure (a rectangular megalithic compound containing the Gateway of the Sun), the semi-subterranean temple, the Puma Punku platform (the subject of this file), and a substantial residential and ceremonial outer zone. The complex covers an area of approximately 4 square kilometers, of which a small fraction has been excavated. Verified [1]

Tiwanaku as a state polity emerged in the southern Lake Titicaca basin in approximately 500 CE, expanded into a regional hegemony during the period 600–1000 CE, and collapsed around 1000–1100 CE. The Tiwanaku political and cultural system is the principal pre-Inca Andean state of the Lake Titicaca region; its iconography and architectural conventions are continuous with and ancestral to elements of subsequent Andean cultures.

The dating

Radiocarbon dates from sealed contexts within the Puma Punku platform substructure converge on a principal construction period of approximately 536–600 CE. Verified Specific date series include: charcoal recovered from the platform fill during the Ponce Sanginés excavations of the 1960s; organic material from below the platform's stone facing recovered during Kolata's project work; and dates from associated features in the broader Tiwanaku stratigraphy. The 6th-century date places Puma Punku in the late Tiwanaku III to early Tiwanaku V cultural-chronological horizon and is considered well-established in mainstream Andean archaeology [2].

An older claim — advanced principally by the Bolivian researcher Arthur Posnansky in publications from 1914 onward — placed Tiwanaku at extreme antiquity (Posnansky variously proposed dates as old as 15,000 BCE). Posnansky's dating rested on archaeoastronomical inference from supposed astronomical alignments of the Kalasasaya enclosure; subsequent radiocarbon work has decisively contradicted his proposed dates. The Posnansky framework is no longer taken seriously in mainstream Andean archaeology but persists in popular fringe writing about the site.

The component stones

The Puma Punku platform's stonework consists of two main lithological categories: Verified [3]

• Red sandstone. Used for the largest platform-facing blocks and for the H-blocks. Quarried from sources at relatively close range to the site (the Kausani quarries within approximately 10 km).
• Andesite. Used for the most precisely-worked architectural elements and for some smaller blocks. The principal andesite source has been identified petrologically as the volcanic deposits of the Copacabana Peninsula, approximately 90 km from Tiwanaku across the southern arm of Lake Titicaca.

The largest single block at Puma Punku has been measured at approximately 7.81 meters long, 5.17 meters wide, and 1.07 meters thick, with an estimated mass of approximately 131 metric tons. Other very large blocks include several in the 30–90 ton range. The cumulative mass of the platform's stone facing and structural elements has been estimated at approximately 6 million kilograms (6,000 tons). These figures are based on the surviving stonework; the original platform mass would have been substantially greater.

The H-blocks

The H-blocks (also called "stepped blocks" or "interlocking blocks") are a distinctive Puma Punku architectural element. They are carved sandstone modules whose plan view forms an "H" or square-stepped pattern, with cut faces that interlock with corresponding cuts on adjacent blocks. The interlocking design provides both structural function (resistance to seismic shear, which is a real concern at the elevation and tectonic setting) and likely aesthetic intention. Verified

The H-blocks are notable for their cutting precision. The best-preserved examples show interior angles cut to within tolerances of the order of one millimeter across distances of tens of centimeters; the parallel faces are flat to within similar tolerances. This precision has been the focus of much of the popular alien-construction commentary. The mainstream archaeological view is that the precision is consistent with sustained stone-pounding technique by trained Andean masons over extended production timescales; recent precision-laser-scanning re-measurement projects (from approximately 2018 onward) have produced detailed metric documentation of the surviving H-blocks that supports rather than challenges the human-construction reading. The scanning has shown that the H-blocks, while precisely cut, are not identical to one another in the way machine-produced parts would be; they show the small individual variations consistent with hand production within a master template tradition [4].

The construction tools and techniques

No metal tools capable of working andesite or hard sandstone were available to the Tiwanaku state polity. Copper and bronze were known to the Andean cultural sphere in the relevant period, but these metals are too soft to work hard stone effectively. The Tiwanaku stoneworkers used a combination of techniques whose evidence is preserved on partially-completed and discarded blocks at the site and at the quarries: Verified

• Stone-pounding with hammerstones. The principal cutting and shaping technique. Hammerstones of hard volcanic stone (commonly basalt or river-cobble quartzite) were used to pound the surface of softer andesite or sandstone, removing material gradually. Production debris from this technique is abundant in the workshop areas around the site.
• Wet grinding with abrasive sand. Used for final smoothing and for the precise interior cuts of the H-blocks. The technique uses water-suspended quartz sand as an abrasive against a harder grinding surface, producing the smooth flat surfaces that characterize the most precisely-worked elements.
• Drilling. Some Puma Punku blocks show evidence of drilled holes used for fitting metal cramps (small bronze or copper joints that locked adjacent blocks together). The drilling was done with hand-rotated drills using sand abrasive.

The transport of the large blocks from the quarries to the site is the technical question with the least complete reconstruction. The 90-km distance from the Copacabana andesite quarries to Tiwanaku is the principal transport challenge. Proposed methods include: log-roller transport over land segments; raft transport across the lake (Lake Titicaca's southern arm provides a natural water corridor); inclined-plane techniques for the final positioning. Experimental archaeology by Jean-Pierre Protzen and others has demonstrated the feasibility of moving multi-ton blocks using rollers, sleds, and organized labor groups in the hundreds, consistent with the production rates the Tiwanaku state would have required for the construction. Verified at the level of feasibility; Claimed at the level of the specific method used.

The excavation history

Puma Punku and the broader Tiwanaku complex have a long professional excavation history. Verified Key phases: [5]

• Wendell Bennett (1932). Bennett, then at the American Museum of Natural History, conducted the first stratigraphic excavation at the complex. His work established the basic chronological framework and identified the principal architectural elements. Bennett's monograph (Excavations at Tiahuanaco, 1934) is the first modern professional study.
• Carlos Ponce Sanginés (1957–1972). Ponce, a Bolivian archaeologist, directed the largest sustained excavation program at the site, including extensive work at Puma Punku. His tenure also included substantial reconstruction work, some of which has been subsequently criticized for over-reconstruction without adequate documentation of the original state. The Ponce work substantially expanded the radiocarbon dating series and the architectural reconstruction.
• Alan Kolata (1980s–2000s). Kolata, of the University of Chicago, directed multi-decade investigations focused on the broader Tiwanaku polity and its agricultural and hydraulic systems. Kolata's work integrated the site into a comprehensive picture of the Tiwanaku state's organization and collapse.
• 2010s–present. Continuing investigations under Bolivian and international collaboration. Precision laser-scanning projects from approximately 2018 onward have produced detailed metric documentation of the H-blocks and other elements.

The state polity

The Tiwanaku state at its peak (approximately 600–1000 CE) controlled a regional sphere extending across portions of present-day Bolivia, Peru, and northern Chile. The state was characterized by intensive raised-field agriculture in the Lake Titicaca basin, llama-caravan trade networks, an elite-managed religious-iconographic system, and the construction of monumental ceremonial architecture at the capital. The estimated peak population of the Tiwanaku capital itself has ranged from 30,000 to 60,000 in various scholarly estimates. Verified [6]

This is the political and demographic context in which the Puma Punku platform was constructed. A state polity of the size and organizational complexity attested for Tiwanaku had the labor base, the iconographic-ideological motivation, and the technical-mason tradition required for the construction. The construction is not a single-generation or short-term project; the platform construction is consistent with sustained labor over decades, of the kind documented for comparable mainstream state-level monumental construction worldwide.

The site abandonment and post-abandonment

Tiwanaku declined and was substantially abandoned around 1000–1100 CE, for reasons that are the subject of continuing scholarship but that appear to combine climatic deterioration (a late-Holocene drying trend documented in lake-sediment paleoclimate proxies), agricultural-system stress, and political reorganization. The Puma Punku platform was abandoned at roughly the same time. Verified

From abandonment forward, the site was subject to substantial stone removal. The Spanish colonial period (16th–19th centuries) and the early Republican period drew on Tiwanaku stone for construction projects in La Paz and adjacent cities; the Bolivian-period rail line and other infrastructure also incorporated removed stone. The site was further damaged by seismic events and by the conventional natural weathering processes. By the time professional excavation began in 1932, the surviving structure was a substantially reduced fraction of the original. The Bolivian Ministry of Cultures has documented the stone-removal history through colonial archival research and through identification of Tiwanaku stones in subsequent construction. Verified [7]

The von Däniken framing

Erich von Däniken's Chariots of the Gods? (German original 1968; English translation 1969) is the modern starting point of the popular alien-construction interpretation of Puma Punku, alongside many other ancient sites. Von Däniken's argument, in the form applied to Puma Punku: the precision of the H-block joinery and the mass of the largest blocks exceed what pre-industrial human societies could plausibly achieve; therefore the construction was assisted by visitors of non-terrestrial origin. The argument has been extended across Chariots's many successor titles and has been the focus of the History Channel's Ancient Aliens series (2009 onward) treatment of the site. Claimed

Why this fails: The argument is structurally a residual-mystery argument: it identifies a feature of the site that is impressive, infers that human construction is impossible, and concludes for non-human construction. The inference step is unsupported. The precision and mass of the stonework are consistent with the documented capabilities of mainstream Andean stonemasonry, demonstrated experimentally and by reference to comparable construction at later Andean sites (Sacsayhuamán, Ollantaytambo, Machu Picchu, all of which include large precision-cut blocks produced without metal tools or wheeled transport). The presence at the site of partially-completed blocks showing the stone-pounding production sequence, the abundance of workshop debris, and the comparable mason-tradition evidence at adjacent Tiwanaku sites provide positive evidence for the conventional explanation. The von Däniken framing requires ignoring all of this positive evidence in favor of an inference from the impressiveness of the result.

The Brien Foerster framing

Brien Foerster, a Canadian-born popular writer based in Peru, has produced extensive self-published and online material on Puma Punku and adjacent Andean sites since approximately 2009. Foerster's framing, in its current form: the precision of the work is consistent with machining-tool technology rather than stone-pounding; the H-blocks are evidence of a lost pre-Tiwanaku civilization with advanced technology; the Tiwanaku polity inherited but did not produce the most impressive elements. Claimed

Why this fails: The lost-predecessor reading has the structural difficulty that no archaeological evidence exists for a pre-Tiwanaku polity in the southern Lake Titicaca basin with the proposed technical capabilities. The stratigraphy of the site shows continuous Tiwanaku-period construction; there is no archaeological horizon corresponding to the proposed predecessor. The "machining tool" interpretation of the cut surfaces has been examined by Protzen, Stanish, and other mainstream Andean archaeologists, who have demonstrated experimentally that the surface features are reproducible with the documented Tiwanaku tool-kit. The Foerster framing is a more recent version of the same residual-mystery argument that von Däniken introduced; it has not engaged substantively with the positive evidence the archaeology has produced. Unverified.

The mainstream interpretations and the popular claims.

Mainstream: late-Tiwanaku state monumental architecture

The current Andean-archaeological consensus interprets Puma Punku as the product of the Tiwanaku state polity, constructed during the 6th-century horizon, using organized labor with stone-pounding tools and inclined-plane transport, and abandoned at the end of the Tiwanaku period for reasons related to the broader state collapse. Verified as the consensus.

The "lost technology" / fringe claim

Variants of the von Däniken and Foerster framings: the construction technology exceeded what 6th-century Andean peoples could have produced; therefore some other explanation (extraterrestrial assistance, lost predecessor civilization, advanced unknown technology) is required. Claimed

Where it stands: Not supported by the archaeological evidence. Inconsistent with the documented Tiwanaku-period stratigraphy, the workshop-debris and partially-completed-block evidence for the conventional production technique, the experimental-archaeology demonstrations of feasibility, and the comparable precision-stoneworking at related Andean sites. Unverified.

The Posnansky deep-antiquity claim

Arthur Posnansky's early-20th-century proposal that Tiwanaku dates to many thousands of years BCE, based on archaeoastronomical inference. Claimed

Where it stands: Decisively contradicted by the radiocarbon record. Persists in popular fringe writing but not in mainstream archaeology. Disputed in the sense that fringe writers continue to advance it; the mainstream-archaeological treatment is that it has been refuted.

The genuine open technical questions

Distinct from the fringe claims. Real archaeological questions on which mainstream researchers continue to work: Claimed as open questions.

• The precise transport method for the largest andesite blocks across the 90-km distance from the Copacabana quarries to the site.
• The exact original architectural configuration of the structures atop the platform (substantially destroyed by post-Tiwanaku stone removal, so reconstruction is partial).
• The social organization of the labor force (e.g., corvée labor by tributary populations, full-time mason corps, ritual-pilgrimage labor contribution, or some combination).
• The specific ritual or political function the platform served within the broader Tiwanaku ceremonial complex.
• The reasons for the late-period abandonment.

These are real questions. They are the questions the field is actually working on. They are not paranormal questions.

The unanswered questions.

The transport pathway from Copacabana

The single most consequential technical question. The largest andesite blocks were quarried at Copacabana and transported approximately 90 km to Tiwanaku. The transport probably included a substantial water-borne segment across the southern arm of Lake Titicaca and overland segments on each end. The specific roller, sled, or raft mechanism, and the labor scale required, have been the subject of extensive experimental-archaeology investigation but not directly documented in the surviving Tiwanaku material record. The Tiwanaku polity left no written records (no pre-Inca Andean civilization had writing of the kind that would document such an engineering enterprise); the question can only be approached indirectly through experimental work and through the surviving partially-completed and abandoned blocks along plausible transport routes.

The original architectural superstructure

The Puma Punku platform was the substructure for an architectural complex atop it. The configuration of that complex — the specific arrangement of walls, gateways, internal spaces, and ritual installations — is partially reconstructed from the surviving stonework and partially from analogy to related Tiwanaku sites, but the original built form is not fully recoverable. The Ponce-era reconstructions made architectural choices that have been criticized for incorporating elements without adequate documentary support; current Bolivian Ministry of Cultures policy is conservative about further reconstruction.

The Akapana-Puma-Punku relationship

The Akapana platform and the Puma Punku platform are the two principal monumental constructions of the Tiwanaku complex. They differ in size, construction technique, and orientation. The functional and chronological relationship between the two — whether they were sequential phases of the same ceremonial program, contemporaneous parallel constructions serving different functions, or in some other relationship — is not fully resolved. The ongoing excavation work at both sites is gradually producing better answers but has not closed the question.

The social organization of the labor

The cumulative labor required for the platform construction is large — on the order of thousands of person-years — but is consistent with the documented capabilities of the Tiwanaku polity. Whether the labor was organized through corvée obligation by the Tiwanaku state's tributary populations, through ritual-pilgrimage contribution by religious devotees, through specialized full-time mason corps, or through some combination, is not fully established. Indirect evidence (the workshop-debris distribution, the consistency of mason-tradition technique across the site, the broader Tiwanaku political-economic record) supports a mixed-organization reading but does not resolve the specific configuration.

The reasons for the abandonment

Puma Punku was abandoned in the broader Tiwanaku state collapse of approximately 1000–1100 CE. The drivers of that collapse — the late-Holocene drying trend documented in regional paleoclimate proxies, the agricultural-system stress that followed, the political reorganization — are partially documented but the specific combination of factors and the specific terminal events at Puma Punku itself are not fully reconstructable. The post-abandonment stone-removal complicates the question by removing evidence that might otherwise have been informative.

Primary material.

• The site itself, currently under the management of the Bolivian Ministry of Cultures and Tourism. UNESCO World Heritage Site since 2000.
• Excavated finds held at the Tiwanaku Site Museum (on-site), the National Museum of Archaeology in La Paz, and (for historical finds removed in the early 20th century) various international museum collections.
• Bennett, W.C. Excavations at Tiahuanaco. Anthropological Papers of the American Museum of Natural History, Vol. 34, Pt. 3, 1934. The first modern stratigraphic study.
• Ponce Sanginés, Carlos. Multiple publications throughout 1957–1972 and beyond, including the 1971 Tiwanaku monograph. Continuing as the principal Spanish-language source on the mid-20th-century excavation program.
• Kolata, Alan L. (ed.). Tiwanaku and Its Hinterland: Archaeology and Paleoecology of an Andean Civilization, Volumes 1 and 2 (Smithsonian Institution Press, 1996 and 2003).
• Protzen, Jean-Pierre, and Stella Nair. Multiple publications on Tiwanaku and Inca stonework, including The Stones of Tiahuanaco (Cotsen Institute, 2013).
• The 2018-onward precision laser-scanning project documentation (multiple academic teams; results published in Journal of Archaeological Science and conference proceedings).
• UNESCO World Heritage Nomination File for Tiwanaku, 2000.
• Radiocarbon date series for Tiwanaku, published in Latin American Antiquity, Andean Past, and other peer-reviewed venues.

The sequence.

1. ~500 CE Emergence of the Tiwanaku state polity in the southern Lake Titicaca basin.
2. ~536–600 CE Principal construction phase at Puma Punku, per radiocarbon dating of sealed-context organic material.
3. ~600–1000 CE Tiwanaku state at its regional-hegemonic peak.
4. ~1000–1100 CE Tiwanaku state collapse. Puma Punku abandoned.
5. ~1100–1532 CE Post-Tiwanaku period. Andean cultural reorganization eventually producing the Inca polity (15th century). Tiwanaku ruins venerated as sacred but not occupied as a state center.
6. 1532 CE Spanish conquest of the Inca empire begins. Tiwanaku encountered in ruin by Spanish chroniclers (Pedro Cieza de León's description in the 1550s).
7. 16th–19th centuries Colonial-era and Republican-era stone removal from Tiwanaku for construction projects.
8. 1914 onward Arthur Posnansky's deep-antiquity claims published. Eventually contradicted by radiocarbon dating.
9. 1932 Wendell Bennett's first modern stratigraphic excavation.
10. 1957–1972 Carlos Ponce Sanginés's sustained excavation and reconstruction program.
11. 1968 Erich von Däniken publishes Chariots of the Gods?, popularizing the alien-construction framing for Puma Punku and many other sites.
12. 1980s–2000s Alan Kolata's University of Chicago project work.
13. 2000 Tiwanaku inscribed on UNESCO World Heritage List.
14. 2009–present History Channel's Ancient Aliens series treats Puma Punku as a featured site.
15. 2018–present Precision laser-scanning re-measurement projects produce detailed metric documentation of the H-blocks and other elements.
16. 2020s Continuing excavation and analysis. Bolivian Ministry of Cultures policy emphasizes conservative interventions.

Cases on this archive that connect.

The Antikythera Mechanism (File 011) — the parallel question of an artifact whose technical sophistication exceeded what was attributed to its producing culture before careful study. The Antikythera case is instructive for showing how mainstream scholarship has reckoned with technical surprise: by expanding the picture of the culture's capabilities rather than by inferring extra-human contribution. The same analytical move applies to Puma Punku.

Göbekli Tepe (File 012) — structural parallel: a megalithic site built by a culture whose capabilities had been underestimated. Göbekli Tepe (~9600 BCE) and Puma Punku (~6th century CE) sit at opposite ends of the megalithic-architecture timeline but share the analytical pattern of impressive construction by a culture that the archaeology has subsequently shown was substantially more organized and capable than had been assumed.

The Nazca Lines (File 059) — the Andean parallel: a sophisticated pre-Columbian Andean ceremonial construction whose interpretation has been the subject of both serious archaeological work and persistent popular fringe-extension claims. The same balance applies to Puma Punku: real archaeological work, real popular misframing, and a need to distinguish between them.

The Sphinx Weathering Hypothesis (File 071) — for the analytical contrast. Sphinx weathering is a non-consensus minority hypothesis with credentialed proponents; the Puma Punku alien-construction framings are popular fringe claims without comparable scholarly base. The cases are instructive together for distinguishing the two categories.

Atlantis (File 057) — for the broader popular-fringe context in which the Puma Punku alien-construction and lost-predecessor claims circulate. Both narratives serve the broader popular framework of pre-historical advanced civilizations whose evidence has been lost or suppressed.

Planned: a standalone file on the broader Tiwanaku polity as a pre-Inca Andean state; a file on the Sacsayhuamán megalithic Inca site for comparison.

Full bibliography.

1. Bennett, Wendell C. Excavations at Tiahuanaco. Anthropological Papers of the American Museum of Natural History, Vol. 34, Pt. 3, 1934.
2. Ponce Sanginés, Carlos. Tiwanaku: Espacio, Tiempo y Cultura. Academia Nacional de Ciencias de Bolivia, La Paz, 1971; and multiple subsequent monographs.
3. Kolata, Alan L. The Tiwanaku: Portrait of an Andean Civilization. Blackwell, 1993.
4. Kolata, Alan L. (ed.). Tiwanaku and Its Hinterland: Archaeology and Paleoecology of an Andean Civilization, Volumes 1 (1996) and 2 (2003). Smithsonian Institution Press.
5. Protzen, Jean-Pierre, and Stella Nair. The Stones of Tiahuanaco: A Study of Architecture and Construction. Cotsen Institute of Archaeology Press, UCLA, 2013.
6. Protzen, Jean-Pierre, and Stella Nair. "Who taught the Inca stonemasons their skills? A comparison of Tiahuanaco and Inca cut-stone masonry." Journal of the Society of Architectural Historians 56, 146–167 (1997).
7. Vranich, Alexei. "The construction and reconstruction of ritual space at Tiwanaku, Bolivia (A.D. 500–1000)." Journal of Field Archaeology 31, 121–136 (2006).
8. Vranich, Alexei. "Reconstructing ancient architecture at Tiwanaku, Bolivia." Heritage Science 6, 65 (2018). (On the precision-laser-scanning approach to the H-blocks and adjacent elements.)
9. Janusek, John Wayne. Identity and Power in the Ancient Andes: Tiwanaku Cities through Time. Routledge, 2004.
10. Stanish, Charles. Ancient Titicaca: The Evolution of Complex Society in Southern Peru and Northern Bolivia. University of California Press, 2003.
11. Ortloff, Charles R., and Alan L. Kolata. "Climate and collapse: agro-ecological perspectives on the decline of the Tiwanaku state." Journal of Archaeological Science 20, 195–221 (1993).
12. UNESCO. Nomination File for Tiwanaku: Spiritual and Political Centre of the Tiwanaku Culture, 2000.
13. von Däniken, Erich. Chariots of the Gods? Unsolved Mysteries of the Past. Putnam, 1969 (English translation of 1968 German original). The popular alien-construction framing.
14. Feder, Kenneth L. Frauds, Myths, and Mysteries: Science and Pseudoscience in Archaeology, 9th ed., Oxford University Press, 2018. Includes a treatment of the Puma Punku alien-construction claims.
15. Posnansky, Arthur. Tihuanacu: The Cradle of American Man, Volumes 1 and 2, J.J. Augustin, 1945. The deep-antiquity claim; subsequently contradicted by radiocarbon dating.