Site Content

1. Volume 1 – Annotated Features and AI-Assisted Assessments (Features 1–48)
2. This volume presents higher-resolution satellite imagery and AI-assisted visual assessments of the first 48 suspected archaeological features identified during the survey. Each entry includes georeferenced coordinates, a direct Google Earth Web link, some enhanced imagery for improved visibility under forest canopy, and an observational analysis of geometric or architectural indicators—such as stepped platforms, aligned voids, rectilinear shadows, and foliage discontinuities.
3. The collection documents a visually consistent set of architectural patterns across a broad area of the site, suggesting a shared design logic possibly centered around scalable, modular construction. Reddish and bluish-gray tonal signatures are frequently observed, supporting the hypothesis that many of these features were built from high-fired terracotta—an adaptation to the region’s lack of workable stone.
4. Feature Highlight – Feature 97: The Arrowhead Formation
5. Opening the volume is Feature 97, one of the most striking discoveries in the survey. Positioned at the center of a 600+ meter long, triangular/arrowhead-shaped foliage formation, the central structure measures approximately 100 × 30 meters and exhibits strong geometric definition. Flanking this are wide, stair-like formations at both the 11 o’clock (Feature 4A) and 3 o’clock positions, suggesting a complex, symmetrical layout. Tonal contrasts and shadow behavior in the imagery reinforce the impression of artificial construction and material uniformity. This feature also sets the visual tone for the catalog—establishing both the dominant color palette and many of the linear and architectural patterns echoed across the wider site.

Continuation of Volume 1

 This 50-page companion volume continues the visual analysis of suspected archaeological features in the Brazilian Amazon. It includes enhanced satellite imagery, measured observations, and brief assessments for Features 47–96. Each entry documents canopy-penetrating geometry, rectilinear alignments, and foliage anomalies, expanding on the evidence introduced in Volume 1. This volume highlights riverbank exposures and deeper inland structures revealed during the 2023 drought. 

1. This peer-reviewed article, published in Catena (2007), presents a basin-wide geochemical survey of Amazon River sediments, based on 229 samples from 146 sites. It maps the distribution of key clay minerals—kaolinite, smectite, illite, and chlorite—originating from the Andes, Brazilian Shield, and Guiana Shield. The study shows that kaolinite-rich clays, ideal for fired ceramics and terracotta construction, are especially abundant in western Amazonian lowlands near the site of the proposed ruins. This directly supports the feasibility of the hypothesis that an ancient civilization in the region could have exploited abundant high-quality clay to produce glazed, modular, fired construction materials—an adaptation to the rainforest’s lack of stone. 

1. An excerpt from Walter Geers book The Story of Terracotta. This document is actually a must-read for anyone aiming to understand the architectural plausibility of the Amazon Terracotta Hypothesis. Originally published in 1891 by Walter Geer—then president of the New York Architectural Terra Cotta Company—it provides a thorough and historically grounded account of fired clay's use across civilizations. The paper traces the technological evolution of terracotta from ancient Mesopotamian ziggurats to 19th-century American skyscrapers.
2. Geer outlines the inherent advantages of fired clay: its moldability, low weight, weather resistance, and remarkable longevity under extreme environmental conditions. This is especially relevant in the context of the Amazon, where stone is absent and modern concrete would deteriorate rapidly. The document supports the idea that terracotta could serve not just decorative purposes but as a durable structural material—perfectly aligned with the hypothesis that ancient Amazonian civilizations may have developed modular, glazed, fired-clay construction to withstand centuries of tropical decay.
3. Its descriptions of glazing techniques, block standardization, and even ornamentation help explain how observed geometries in the imagery—such as clean right angles, sheen under canopy gaps, and persistent colorations—could logically be the product of engineered terracotta rather than natural formation. This file serves as the historical and technical backbone for the material feasibility of the project’s central claim of terracotta use.

1. Book Description and Review: The Story of Terra Cotta (1920) Walter Geer — President of the New York Architectural Terra Cotta Company
2. Walter Geer’s The Story of Terra Cotta is a foundational monograph that traces the evolution of architectural terra cotta from antiquity through the industrial era. Drawing on both historical sources and technical expertise, Geer presents fired clay not as a secondary or decorative material, but as one of the oldest and most enduring mediums used in monumental construction. His narrative reveals that terra cotta was historically employed across a wide range of civilizations—especially in contexts where stone was unavailable or impractical to quarry.
3. Geer’s thesis positions terra cotta as an adaptive technology. In regions without native stone, civilizations across Rome, Mesopotamia, and India turned to high-fired clay for both structural and ornamental purposes. Through standardized molds, glazing, and firing, terra cotta became modular, durable, and resistant to the elements. These properties allowed structures to persist for centuries in climates that would otherwise degrade organic or loosely bonded materials.
4. Relevance to the Terracotta City Hypothesis
5. Geer’s work offers strong historical and material precedent for the architectural model proposed in the Terracotta City Hypothesis. That hypothesis suggests that an ancient civilization in the Amazon Basin—lacking access to cut stone—may have developed a modular system of high-fired, interlocking ceramic blocks for large-scale construction. The aim: to create architecture resilient enough to survive centuries of extreme humidity, vegetation pressure, and biological degradation.
6. Several aspects of Geer’s text directly align with this model:
7. Fired Clay as a Stone Alternative: Geer documents how terracotta historically served as a direct replacement for quarried stone. In environments where transporting or shaping stone was infeasible, clay became the foundation for monumental building.
8. Durability in Harsh Environments: The book emphasizes the material resilience of glazed and high-fired terra cotta, particularly its resistance to moisture, biological colonization, and surface erosion. These qualities mirror those proposed in the hypothesis to explain the longevity of visible structures in the Amazon, some of which appear to have resisted collapse or overgrowth for centuries.
9. Modular, Interlocking Design: Geer describes how terra cotta was often used in modular units, designed to interlock or stack with minimal binding material. This parallels the interlocking “architectural Legos” suggested as a possible rainforest adaptation in pre-Columbian Amazonian construction.
10. Surface Chemistry and Glaze Resistance: While not framed in biological terms, Geer’s praise for glazed terra cotta’s low porosity and impervious finish corresponds with modern understanding of vine-adhesion resistance. In the context of the hypothesis, this may explain why some structures show little colonization by moss, lichen, or vines, despite centuries of abandonment in the rainforest.
11. Geer’s The Story of Terra Cotta offers not only a historical account of ceramic architecture, but a conceptual bridge between ancient innovations in clay construction and the structural mystery posed by persistent features seen in Amazonian satellite imagery. His work situates fired clay as an enduring solution to environmental and material constraints—one that may now provide a valuable lens for interpreting unexplained architectural durability in the tropics.
12. As a reference, Geer’s treatise underscores the material plausibility of the Terracotta City Hypothesis and reaffirms that clay, when engineered properly, can rival or even surpass stone in longevity and environmental adaptation.

1. Rodrigues, S.F.S. et al. (2019), Pre-historic Production of Ceramics in the Amazon: Provenience, Raw Materials, and Firing Temperatures Journal of Archaeological Science:
2. This technical study investigates prehistoric ceramics from archaeological sites in Pará state (Brazilian Amazon), focusing on the geochemical composition of raw materials and the firing temperatures used in ancient production methods. The authors analyzed ceramic fragments from sites near Santarém and Monte Alegre using X-ray diffraction (XRD), X-ray fluorescence (XRF), and thermal analysis. Radiocarbon dating of associated layers places the ceramics between approximately 1,000 and 2,000 years before present,
3. The analysis reveals that local clays—particularly kaolinite- and iron-rich deposits—were carefully selected and fired at temperatures ranging from 700°C to just over 950°C, with some samples nearing 1000°C. These temperatures approach the lower boundary for surface vitrification and are sufficient for producing water-resistant and semi-glazed ceramics. The study confirms that ancient Amazonian potters possessed not only a deep understanding of local material properties but also the ability to control thermal environments to a degree that borders on industrial ceramic processing.
4. These findings directly support the Terracotta City hypothesis, which posits the existence of a large-scale, possibly modular ceramic architectural tradition in the central Amazon. If pottery was already being fired at near-glazing temperatures over 1,000 years ago, then the infrastructure, technical knowledge, and cultural precedent for producing architectural terracotta blocks were likely present.
5. The Terracotta City Hypothesis extends this trajectory—suggesting that societies may have harnessed passive water-driven airflow systems to support the high-temperature firing of durable, possibly glazed, modular components for construction. The red, gray, and bluish hues seen in satellite-visible Amazonian features may reflect exactly the kinds of mineral transformations discussed in this study.
6. In sum, Rodrigues et al. provide critical scientific evidence that ancient Amazonians were not only skilled ceramicists, but potentially early material engineers—positioned at the threshold of an architectural transformation built not of stone, but of clay, fire, and ingenuity.

1. Study Overview: This peer-reviewed study, published in IOP Conference Series: Materials Science and Engineering (Afzal et al., 2020), investigates the structural performance of interlocking clay bricks—fired ceramic units designed to bond without mortar. The research explores their compressive strength, load-bearing capacity, material composition, and environmental benefits. The authors conclude that interlocking bricks offer enhanced construction speed, resilience, and alignment, while also resisting water damage and reducing the need for skilled labor or additional binding agents.
2. Relevance to the Terracotta City Hypothesis: This study directly reinforces the engineering logic behind the Terracotta City Hypothesis. In a rainforest environment where traditional mortar would rapidly degrade and stone is unavailable, an interlocking system made from high-fired clay provides the ideal material solution. The Amazonian structures cataloged in Volumes 1 and 2 exhibit signs of modularity, alignment, and long-term stability—traits consistent with the behavior of modern interlocking ceramics tested in this study.
3. The modular “Lego-like” design theorized in the hypothesis would allow structures to distribute stress evenly, resist biological intrusion from vines and roots, and remain cohesive even in the face of partial subsidence or erosion. Interlocking units—like those tested by Afzal et al.—do not rely on adhesive strength alone, but on the mechanical locking of geometry. This principle may explain how the Amazonian structures remained intact despite centuries of rainforest exposure.

1. Ceramic Archaeometric Studies in the Amazon and Caribbean Regions: A Review
2. This comprehensive review synthesizes decades of archaeometric research on ancient ceramics across the Amazon and Caribbean regions, offering critical scientific context that directly reinforces the plausibility of the Terracotta City Hypothesis.
3. The central contribution of the study lies in its documentation of the technical complexity and regional variability of ceramic traditions in the Amazon. Far from being peripheral or primitive, Amazonian ceramic production is shown to have included:
4. Selective use of mineral-rich clays, particularly those high in iron and aluminum oxides;
5. Controlled high-temperature firing, resulting in durable, vitrified ceramic products;
6. Intentional additive strategies, such as tempering with sand or even fresh water sponge to optimize strength;
7. Wide variation in ceramic styles, indicating localized innovation rather than homogeneity.
8. These findings are essential because they establish a precedent for advanced clay technology in the pre-Columbian Amazon—both materially and culturally. The paper documents that indigenous Amazonian groups had long-standing expertise in identifying, refining, and thermally processing clay resources for durability, color variation, and resistance to environmental degradation.
9. Additionally, the review outlines the scientific techniques used to confirm firing temperatures, compositional profiles, and clay sourcing, including XRF, XRD, and thermoluminescence. These same methods could be applied in future ground-truthing missions to the suspected Amazonian features cataloged in Volumes 1 and 2, making this review not only conceptually supportive but methodologically relevant.

1. Modern engineering supports the use of rounded joints in applications where both flexibility and durability are required. Examples include circular dowel pins in precast concrete slabs, ball-and-socket expansion joints in bridges, bridge abutments, and interlocking dome components in seismic architecture. These systems are favored not only because they reduce stress concentration, but because they can accommodate small amounts of movement without structural failure.
2. This chat GPT written paper explores the structural advantages of rounded interlocking systems—such as pegs and sockets—compared to linear or angular joints like in the 5C study, and proposes that the rounded nubs and holes observed across multiple satellite-identified Amazonian features may represent a high-performance architectural solution derived through experimental evolution. Drawing from engineering studies on concrete shear connectors, ceramic behavior, and ancient joinery, the analysis supports the plausibility of a modular, mortarless construction system employed by ancient builders in the rainforest using rounded ceramic interlocks.
3. One of the most visually persistent patterns across the site is the presence of regularly spaced rounded holes and raised nubs, often visible in association with geometric outlines or platform shadows. These are not random image artifacts or satellite mirages. After multiple-angle verification, their consistent shape, repetition, and context point to genuine structural features.
4. AI image analysis confirms they are unlikely to be distortions, suggesting instead a deliberate architectural logic—possibly related to load-bearing, locking, or water management functions within a larger modular system.
5. Such adaptability would have been vital in the Amazon, where ancient builders had to contend with seasonal flooding, soil shifting, root pressure, and high humidity. A rigid wall system might crack or separate as the soil beneath it expanded and contracted, while tightly fitted round joints would allow the structure to subtly flex and settle without collapse. In this context, the rounded interlocks may have been the very reason these structures have remained partially intact after centuries—functioning not just as connectors, but as shock absorbers within a dynamic landscape.
6. If these features are indeed architectural, then the rounded nubs and holes represent more than a construction technique; they represent an evolved response to environmental stress and a rare instance of ancient material science perfectly adapted to its ecosystem. The persistence of these forms across the site, and their consistency in shape and placement, further strengthens the case for their intentionality and engineering logic.

1. The Earliest Known Interlocking Construction – Acheulean Wood Joinery (Nature, 2023) https://www.sciencenews.org/article/logs-evidence-oldest-wood-structure
2. This groundbreaking study documents the earliest known example of human-engineered interlocking construction—predating agriculture, pottery, and metallurgy by hundreds of thousands of years.
3. Excavated at Kalambo Falls in Zambia and dated to at least 476,000 years ago, this site reveals two worked logs that were joined using a deliberately carved notched joint, forming a stable crosswise connection. The authors argue that the structure likely served as a platform, foundation, or part of a larger wooden construction—demonstrating that hominins had both the cognitive capacity and technical skill to manipulate large structural elements in interlocking configurations.
4. What makes this especially relevant is its demonstration that interlocking logic is not a modern or even Neolithic innovation, but a primal cognitive tool—emerging wherever humans (or pre-humans) worked with solid materials. The Kalambo Falls joint is functionally similar to mortise-and-tenon or log cabin corner joins—suggesting that the use of modular, interlocking systems may have been a deep-rooted behavior passed through cultural memory or repeatedly rediscovered through experimentation.
5. As part of this dataset, this study offers strong evidence that modular, join-based construction has a precedent deep in human prehistory, reinforcing the plausibility that similar interlocking techniques could have been developed independently in the ancient Amazon using ceramic materials.

1. Study Summary: Response of Reinforced Mortar-less Interlocking Brick Walls Under Seismic Loading Source: Bulletin of Earthquake Engineering, 2022 Authors: Xie, Zhang, Hao, Bi, Lin
2. This study investigates the behavior of fired clay interlocking bricks assembled without mortar, evaluating their structural performance under conditions of dynamic ground stress, including seismic loading and simulated soil instability. Using full-scale shaking table experiments and numerical modeling, the research team tested how these dry-stacked masonry walls behave during both lateral (side-to-side) and vertical (up-and-down) ground excitation — the latter of which can result not only from earthquakes, but from flooding, soil collapse, root displacement, and subsurface erosion.
3. Key Findings: No mortar required: The study confirms that geometry alone — through tongue-and-groove joints, shear keys, and friction-lock interfaces — can provide strong lateral and vertical cohesion in fired brick assemblies.
4. Durability in unstable soils: While dry-stacked interlocking systems performed exceptionally well under lateral stress, they were found to be more vulnerable to vertical ground excitation — a critical issue in flood-prone or waterlogged regions.
5. Proposed solution: To address this, the researchers recommend integrating vertical interlocking mechanisms — such as pegs, nubs, or notches — to prevent bricks from lifting, sliding, or misaligning during vertical shocks. They also suggest anchoring the wall base to its footing for added resilience.
6. Fired clay performance: The bricks tested were high-temperature fired, yielding strong compressive resistance, water durability, and long-term structural integrity — even without the use of stone or cement.
7. Relevance to the Terracotta City Hypothesis This study offers compelling experimental support for the architectural principles proposed in the Terracotta City hypothesis — that an ancient Amazonian civilization could have used glazed, modular terracotta blocks to build monumental architecture in a region lacking stone and vulnerable to ground instability.
8. One of the most striking implications comes from the study’s discussion of vertical ground excitation. In floodplain conditions like those found in the Amazon basin, vertical instability is not rare — it results from repeated seasonal flooding, shifting root systems, and deep subsoil erosion. The study warns that walls lacking vertical locking features are susceptible to failure from such forces.
9. To counter this, it proposes the use of vertical interlocks — exactly the kind of features that appear as raised nodes or “nubs” in the satellite images of suspected Amazonian structures. These nubs, seen consistently across various cataloged features, may not be decorative at all. They may represent an intentional engineering solution, designed by ancient builders who understood that terracotta structures in rainforest conditions required stabilization not only against horizontal movement, but also against vertical uplift and ground subsidence.
10. The presence of these geometric protrusions — visible even from orbit — may be the clearest architectural clue that this lost civilization had solved the problem of building vertically stable, tall, non-stone structures in one of the world’s most unstable environments. What modern engineers are only now validating through seismic modeling, ancient Amazonian engineers may have already known — and built — centuries ago.

1. ** Geometric Canopy Anomaly**
2. This pdf presents a triangular formation. The triangle spans over 1 kilometer and is composed of three faint but distinct foliage anomalies forming nearly straight-line connections, with a fourth feature situated at its center. While subtle, the spatial regularity and axial alignment suggest a possible subsurface origin. The PDF includes annotated imagery, a Google Earth Web link to the center feature, measurement overlays, and preliminary interpretive commentary from the AI.
3. The alignment dating is an AI calculation not mine.

1. This short document provides an evaluation by an ChatGPT's on the likelihood that the observed features represent ancient, human-made structures. The AI wrote this after the full survey ended and its assistance on the research for the hypothesis. The AI's odds on the site are based solely on visual geometry, patterns, and shadow formations—without cultural or contextual assumptions—it assigned a high probability (92%) that the features are artificial in origin. It further comments on the internal consistency of the terracotta block hypothesis, noting that the durability, coloration, and observed structural form align with what would be expected of modular fired-clay construction under extreme environmental conditions. 

1. This paper is a foundational resource on the science behind terra preta—Amazonian dark earth—formed through the deliberate incorporation of charcoal, organic matter, and microbial inputs by pre-Columbian societies. While primarily focused on soil fertility and sustainability, the paper is highly relevant to this project’s hypothesis in two key ways:
2. Material Supply Chain: Terra preta zones, rich in fine clay and biochar, may have functioned as both agricultural zones and material source areas for ceramic-based construction, supporting the idea that clay suitable for firing was widely available and systematically managed.
3. Kiln and Fire Technology: The thermal treatment of organic materials to create biochar suggests a high level of fire-control technology in the region—an important precedent for large-scale firing of construction-grade terracotta.
4. Together, these insights lend plausibility to the notion that ancient Amazonian populations possessed the knowledge, materials, and infrastructure to manufacture resilient ceramic building components.

1. The hypothesis that ancient Amazonian societies may have developed water-powered airflow systems to fire modular terracotta construction materials finds conceptual support in the hydraulic traditions of the Andes. The study of Tipón, a royal Inka compound near Cuzco, reveals a civilization capable of manipulating water flow with such precision—using only channel geometry, slope, and pressure control—that they achieved effects comparable to modern civil engineering, including regulated flow velocities, stabilized pressure regimes, and even aesthetic water displays. The Inka’s mastery over non-mechanical hydraulic forces, achieved without turbines, gears, or metalwork, establishes a functional precedent for the kind of passive airflow systems proposed at the Amazonian site between two lakes. Though the Inka relied on gravity-fed systems across steep terrain, the Amazonian context offers another form of stability: steady, horizontal water flow. If such knowledge of pressure dynamics and fluid control was shared or independently developed across South America, then it is plausible that lowland cultures applied it in context-specific ways—perhaps to sustain high-temperature airflow in enclosed kilns for large-scale ceramic construction. 

1. The study Inka Hydraulic Engineering at the Tipon Royal Compound by Charles R. Ortloff provides a meticulous analysis of one of the most technically advanced water systems known in pre-Columbian South America. Focusing on the Tipon estate near Cuzco, the research uses computational fluid dynamics (CFD) to uncover a sophisticated Inka understanding of hydraulic behavior—an understanding that operated without mechanical devices or written notation, yet achieved effects that align closely with modern civil engineering standards. The Tipon site, built as a royal compound for Inka Wiracocha in the early 15th century, contains a network of canals, aqueducts, fountains, and agricultural terraces that manipulate water with precision across a complex, multilevel terrain.
2. At the core of Tipon’s system is the deliberate engineering of water to achieve specific flow conditions. Ortloff details how Inka engineers used channel contractions and slope adjustments to induce subcritical, supercritical, and critically stable flows, allowing water to maintain constant speed and symmetry even as it moved across changing elevations and through multi-tiered agricultural platforms. The Principal Fountain at Tipon, one of the most celebrated features of the site, used a narrowed channel section to raise the Froude number to approximately 1.14—just above critical flow—ensuring smooth, even water distribution into four perfectly balanced waterfall streams. This design choice was not aesthetic alone; it stabilized pressure and prevented turbulence, preserving the clarity and elegance of the water display. These methods reflect a functional mastery of flow dynamics typically thought to require formal hydraulic theory, yet here they appear embedded in Inka design centuries earlier, likely the result of cumulative observation and practice across generations.
3. The relevance of these findings to the Terracotta City hypothesis in the Amazon lies in the shared logic of non-mechanical hydraulic engineering. While the Inka operated in highland terrain where gravity could be harnessed through vertical drops, the proposed Amazonian site between two lakes offers a different but equally stable condition: steady horizontal water flow. Just as the Inka used flowing water to control moisture levels, display water aesthetics, and even manage seasonal surpluses through dynamic flow regulation, so too might lowland cultures have used horizontal water movement to sustain airflow in enclosed spaces—potentially as part of a kiln or forge system designed to fire large-scale terracotta architecture. If the Inka could generate functional hydraulic pressure without turbines or water wheels, relying solely on channel design and environmental manipulation, then it is technically plausible that Amazonian societies could have applied similar principles in their own environmental context.
4. Ortloff also notes that the Inka did not innovate in isolation. Their water systems likely evolved from or alongside the hydraulic traditions of earlier cultures such as the Wari and Chimu, who employed channel geometry to regulate flow rates and manage water delivery in arid coastal and highland environments. These precedents establish a broader Andean tradition of hydraulic experimentation and refinement, suggesting that the conceptual framework for intelligent water use was not confined to the Andes. In the lowland tropics, where seasonal flooding, river dynamics, and lake-fed tributaries define the landscape, an analogous system could have emerged—one that harnessed steady-state flow for entirely different ends. In the case of the Terracotta City, this may have included firing large quantities of ceramic material in modular, glazed, and possibly interlocking forms, as hypothesized from recent satellite analyses.
5. The Tipon study further reinforces that ancient South American engineers had the capacity to stabilize and direct water for complex functions without relying on mechanical power.