The Global Phenomenon of Stone Spheres: New Findings from Zavidovići, Bosnia-Herzegovina and Implications for Prehistoric Technological Knowledge – Featuring the World’s Largest Stone Sphere

1. Introduction

The discovery of nearly perfect stone spheres at sites across six continents has posed a long-standing enigma for archaeology. These spherical megaliths vary in material, size, and location—appearing in Costa Rica, Mexico, New Zealand, Turkey, Russia, Egypt, and notably, Bosnia-Herzegovina—yet consistently demonstrate an exceptional degree of geometric precision and monumentality [1]. While traditional interpretations attribute such formations to natural geological processes like spheroidal weathering or sedimentary concretions [2], emerging evidence points toward artificial origins in several key cases.

The global debate gained prominence with the documentation of over 300 granodiorite spheres in the Diquís Delta of Costa Rica, many exceeding two meters in diameter and up to 20 tons in weight [3]. Their craftsmanship and placement have led researchers to conclude they were intentionally shaped by an unknown culture with advanced capabilities. Similar patterns appear in Mexico’s Jalisco region, the Moeraki Boulders of New Zealand, and volcanic spheres on Easter Island, suggesting a recurring global phenomenon with no clear cultural connection [4,5,6].

In the Balkans, Dr. Sam Osmanagich and the Archaeological Park: Bosnian Pyramid of the Sun Foundation have led systematic research into stone spheres since 2005. Over 20 locations have been identified across Bosnia-Herzegovina, with major concentrations in Zavidovići, Teočak, Zenica, Vareš, and Konjic [7] (see Figure 1, Figure 2, Figure 3, Figure 4, Figure 5, Figure 6, Figure 7, Figure 8 and Figure 9). Among these, the Podubravlje sphere stands out as the largest known stone sphere in the world, discovered in 2016 and estimated to weigh over 37 tons (Figure 9, bottom right).

This paper builds upon previous fieldwork [7,8], petrographic reports by the University of Belgrade (2016), and physical analysis by the University of Tuzla (2016) to present new findings regarding the possible artificial creation of these spheres. It critically reviews prior scientific literature, introduces a comparative global dataset, and reconsiders the spheres’ function, technology, and cultural context.

2. Materials and Methods

This study integrates multi-site field documentation, laboratory analysis, and comparative review to assess the origin, composition, and spatial characteristics of stone spheres across global and Bosnian contexts.

2.1. Field Documentation

From 2000 to 2025, stone spheres were systematically documented at over 50 locations worldwide, including Costa Rica, Mexico, Easter Island, New Zealand, Egypt, Russia, and across the Balkan Peninsula [1,3,5,7]. Key Bosnian sites include Teočak (Figure 7, top left), Zenica (Figure 9, top right), Vareš (Figure 7, bottom right), Slatina, and the primary concentration in Zavidovići and its surrounding villages (Figure 8, Figure 9 and Figure 10). Documentation methods included geolocation (GPS), photographic surveys, physical measurements, stratigraphic observations, and interviews with local residents regarding traditional knowledge and sphere-associated legends.

2.2. Laboratory Analysis

Multiple laboratory analyses were commissioned to determine material composition and density:

• In 2016, the Institute for Geology, University of Belgrade conducted petrographic analyses on samples from broken stone spheres near Zavidovići. Results showed arkosic sandstone with quartz, feldspar, muscovite, magnetite, and iron oxide coatings [8].
• That same year, the Faculty of Mining, Geology and Civil Engineering, University of Tuzla performed density testing on a core sample from the Podubravlje sphere, reporting a specific particle density of 2.64 g/cm³, critical for mass estimation of the 37-ton megalith (Figure 10).
• In 2008, Professor Muhamed Pašić from the University of Zenica conducted a physical-chemical analysis of stone sphere fragments and local natural rock. The test revealed the same nine elements present in both, but only the sphere samples contained manganese (a hardening agent) and calcium oxide (a binder), suggesting artificial enhancement likely consistent with ancient construction using geopolymer techniques [9].

2.3. Comparative Analysis

A global comparative dataset was compiled using published reports, journal articles, and direct field observations. Variables included:

• Sphere material and mineralogy
• Degree of sphericity
• Size and weight ranges
• Environmental context (e.g., buried, surface, clustered)
• Reported cultural associations or alignments

This allowed for side-by-side comparison between spheres in Bosnia (e.g., Podubravlje, Trn, Ponikve), Costa Rica (Figure 1), Mexico (Figure 5, top right), New Zealand (Figure 5, bottom left), and others. Distinctions in material selection and shaping precision were noted across locations, contributing to hypotheses about both convergent and culturally transmitted knowledge.

3. Results

3.1. Discovery of the Podubravlje Sphere

In early March 2016, a team from the Archaeological Park: Bosnian Pyramid of the Sun Foundation began excavations in the village of Podubravlje, located near the town of Zavidovići in central Bosnia. A partially visible stone surface, long known to locals, was gradually uncovered using only hand tools to avoid damage. On March 19, 2016, with media and international visitors present, a major portion of the buried sphere was revealed.

Preliminary measurements of the exposed segment indicated a diameter of approximately 3.8 meters, with an estimated radius between 1.20 and 1.50 meters. Based on material density analysis provided by the University of Tuzla (2.64 g/cm³), the mass of the Podubravlje sphere was estimated to exceed 37 tons, making it the most massive stone sphere ever documented (Figure 9, bottom right; Figure 10).

Stratigraphic observations during excavation revealed layers of sandstone, clay, and soil above the sphere, indicating long-term geological sedimentation. This suggests that the object remained buried for tens of thousands of years, strengthening the case for extreme antiquity.

The sphere’s reddish-brown coloration implies a high iron content. Combined with laboratory results indicating the presence of manganese and calcium oxide—materials not found in nearby natural stone—these findings support the hypothesis that the sphere was artificially created through a primitive geopolymer process. This would involve melting natural stone, incorporating hardening and binding agents, and casting the material in a spherical mold.

The Podubravlje sphere’s size, composition, and context offer compelling evidence that prehistoric cultures in the Balkans may have possessed highly advanced technological knowledge. Its discovery challenges traditional views of prehistoric Europe and raises important questions about forgotten civilizations and their use of geometry, energy, and sacred spatial organization.

3.2. Additional Discoveries in Bosnia-Herzegovina

Beyond Podubravlje, numerous stone spheres have been documented across Bosnia-Herzegovina. In the northeast village of Teočak, eight polished granite spheres were discovered and later cemented into a wall near a mosque (Figure 7, top left). Their large dimensions and unnatural sphericity contrast sharply with natural cannonball-like formations, indicating purposeful shaping.

In Trn and Slatina near Banja Luka, as well as Ponikve and Zenica, additional sandstone and magmatic spheres were found—often embedded several meters below surface level, suggesting considerable age (Figure 8 and Figure 9). One such specimen, split open by construction workers, revealed no internal layering or inclusions, further contradicting the concretion hypothesis. In Zlokuće, spheres are associated with a legendary “Greek cemetery,” and locals believe the stones have healing properties for livestock (Figure 8, top right).

The sphere recovered from the Megara stream in Jablanica (Figure 8, bottom left) and those repurposed in village courtyards (e.g., Vareš, Figure 7, bottom right) illustrate how local populations have interacted with these artifacts, often unaware of their archaeological significance. A petrographic survey conducted in Duboki Potok in 2008 confirmed their arkosic sandstone composition with exotic mineral content and oxidation crusts [9].

3.3. Global Comparisons

Bosnian findings parallel discoveries in other parts of the world. In Costa Rica’s Diquís Delta, over 300 granodiorite spheres—ranging from a few centimeters to 2.5 meters—have been found, many arranged in linear and geometric patterns (Figure 1). Similar examples exist in western Mexico’s Jalisco region, where volcanic stone spheres up to 25 tons were reported, though many were destroyed in the 1960s in treasure hunts (Figure 5, top right). Notably, it is geologically implausible for volcanic processes alone to produce hundreds of perfectly spherical boulders without any irregularly shaped counterparts, which are conspicuously absent at these sites.

The Moeraki Boulders in New Zealand (Figure 5, bottom left) are often cited as natural concretions. However, the scale, density, and precise spherical forms challenge this interpretation. Likewise, Easter Island (Figure 3, left) and Isla del Caño (Figure 4, top left) feature spheres made of volcanic and calcarenite materials—both of which are resistant to natural spherification—raising further doubts about purely geological formation mechanisms.

An important factor across these global discoveries is the diversity of materials used. Stone spheres have been found constructed from at least five distinct geological types: granite, granodiorite, volcanic stone, sandstone, and limestone/calcarenite (coquina). This widespread material variation defies a uniform natural origin and instead points to selective sourcing and intentional shaping by inteliggent hands, adapted to local geological contexts.

In Bosnia, this diversity is evident in the polished granite spheres of Teočak (Figure 7), sandstone examples in Trn and Slatina (Figure 8), and volcanic specimens found near Konjic (Figure 4, bottom right). Crucially, unfinished and partially shaped spheres in locations such as Zenica (Figure 9, top right) provide strong material evidence for a staged production process, including rough shaping followed by smoothing or polishing. The presence of such incomplete artifacts further undermines natural formation theories and suggests an organized, intentional technology.

Unusual discoveries also span Russia, Kazakhstan, Serbia, and even Antarctica (Figure 6). These locations, often lacking contextual archaeological layers, raise questions about either a lost global architectural language or shared prehistoric knowledge. In contrast to the geological diversity of global specimens, the recurring near-perfect spherical geometry strongly supports non-random formation in multiple regions.

Together, these results underline the necessity of reexamining mainstream geological explanations and encourage renewed inquiry into ancient technologies capable of shaping and positioning multi-ton stone spheres across diverse terrains and cultures.

4. Discussion

The findings presented in this study challenge prevailing geological models by introducing robust multidisciplinary evidence that supports the artificial manufacture of at least a portion of the world’s stone spheres. Key indicators include the presence of man-made additives such as calcium oxide and manganese, uniformity in mineral composition, spherical precision far exceeding known natural processes, and the absence of similar unshaped forms in otherwise volcanic or sedimentary regions.

The discovery of the 37-ton Podubravlje sphere (Figure 9) establishes Bosnia-Herzegovina not only as a significant center of this phenomenon but as the location of the largest recorded stone sphere in the world. Its immense mass, stratigraphic context, and unique material properties suggest advanced prehistoric knowledge of materials science, shaping techniques, and environmental integration—principles consistent with what modern scholars might categorize as an early form of geopolymer technology.

These findings add weight to the hypothesis that a now-lost civilization or cultural tradition developed methods of working stone on a monumental scale, far earlier than current historical timelines allow. The recurrence of such spheres in geographically and culturally disparate regions raises critical questions about cultural diffusion, ancient global networks, or parallel technological evolution.

Moreover, the diversity of materials—granite, volcanic, sandstone, limestone, and granodiorite—suggests that the builders adapted to local geologies while maintaining a consistent goal: creating near-perfect spheres. This speaks to shared values or cosmological beliefs associated with the sphere’s geometric and energetic properties.

The role of these stone spheres—whether symbolic, ritualistic, astronomical, or functional—remains open to interpretation. However, evidence of alignment, astronomical referencing (e.g., Figure 2), and anecdotal bioenergetic effects reported at several sites suggest a deeper connection between form, location, and purpose.

Ultimately, this research contributes a structured analytical framework for global stone sphere studies, paving the way for further interdisciplinary research that combines archaeology, geophysics, material science, and cultural anthropology.

5. Conclusions

This research reinforces the argument that many stone spheres discovered across the globe—and especially in Bosnia-Herzegovina—are not the products of natural geological processes but rather the result of intentional, technologically advanced prehistoric craftsmanship. The discovery and analysis of the 37-ton Podubravlje sphere, supported by laboratory analyses and global comparisons, provide compelling evidence for artificial construction methods possibly involving early geopolymer technology.

The spheres’ global distribution, material diversity, perfect geometry, and contextual anomalies challenge conventional archaeological narratives and demand a reassessment of the technological and cultural capabilities of ancient civilizations. Far from isolated anomalies, these artifacts form part of a larger pattern suggesting sophisticated knowledge of material science, energy, astronomy, and symbolism.

Future research should prioritize interdisciplinary collaborations, absolute dating methods, geophysical surveys, and experimental archaeology to deepen our understanding of these enigmatic structures. The Bosnian spheres, and in particular the Podubravlje megalith, offer a unique opportunity to rethink the global heritage of prehistoric engineering and the legacy of civilizations long forgotten.