Ground-penetrating radar surveys at Göbekli Tepe, the ancient stone complex in southeastern Turkey, have identified a large engineered void beneath one of its main enclosures. The space, roughly eight meters long and four meters wide, sits below the site’s central pillars and appears to have been deliberately carved into the bedrock rather than formed by natural processes.

The scans also detected organic material inside the chamber. Researchers have not opened the space, and its contents remain unknown. The discovery has added a new layer to an ongoing re-evaluation of what took place at the site roughly 11,600 years ago.

Göbekli Tepe is widely regarded as one of the most significant archaeological finds of the past century. Excavations since 1995 have uncovered massive T-shaped limestone pillars arranged in circular enclosures, decorated with carvings of animals such as foxes, scorpions, vultures, and snakes. The site predates Stonehenge by about 6,000 years and the Egyptian pyramids by about 7,000 years, and it was built before pottery, the wheel, or agriculture were thought to have emerged.

German archaeologist Claus Schmidt, who led early excavations, interpreted the site as a temple, a gathering place where nomadic hunter-gatherers met for religious ceremonies. That view influenced archaeological thinking for decades. Recent analysis, however, suggests the site may have served a different purpose.

In 2025, a joint German-Turkish team used advanced ground-penetrating radar and AI-assisted analysis to map the subsurface. The scans confirmed that only about 5 to 10 percent of the site has been excavated. At least 20 additional circular enclosures remain buried, potentially containing hundreds more carved pillars. The AI also flagged the void beneath Enclosure D, the largest structure at the site, along with several smaller connected chambers.

The same analysis identified microscopic bone fragments and chemical traces in sediment layers above the void. According to the research team, the concentrations are highest directly above the chamber and decrease with distance, a pattern consistent with repeated activity at that location over time. Sediment cores show organic compounds associated with decomposed human tissue, and mass spectrometry data indicate higher concentrations in layers corresponding to late autumn and early winter. The pattern repeats across multiple strata, suggesting activity occurred on a seasonal schedule over centuries.

Forensic analysis of bone fragments recovered from the site in earlier excavations has provided additional context. A 2017 study published in Science Advances examined 691 human bone fragments from Göbekli Tepe. Three adult skulls showed intentional modification after death, including deep grooves carved into the bone with stone tools. One skull had a drilled hole through the left side, positioned so the skull would hang vertically if a cord were threaded through it. The modifications appear to have been made shortly after death, while the bone was still fresh.

About 10 percent of skull fragments found at the site show cut marks consistent with removal of flesh. Two cervical vertebrae show marks consistent with decapitation. The cuts appear careful and deliberate rather than forceful, and experimental replication suggests the process would have taken 15 to 20 minutes per head. Some skull fragments also show signs of polishing, as if smoothed with a fine abrasive after the flesh was removed.

Skull fragments make up roughly 59 percent of all human bone found at the site, compared with about 15 percent in a typical burial context. No complete human burial has been found at Göbekli Tepe, and no grave goods have been recovered. The evidence suggests the skulls were deliberately retained while most other skeletal remains were discarded.

One of the site’s most studied carvings, Pillar 43 in Enclosure D, depicts a vulture above what appears to be a human head, with a headless human figure below. Surrounding symbols include scorpions, snakes, and geometric shapes. Some researchers now interpret this scene as a depiction of excarnation, the practice of exposing corpses to scavenger birds to remove flesh. Similar practices are documented at other Neolithic sites, including Çatalhöyük, where wall paintings show vultures near headless human bodies.

The vulture carving on Pillar 43 aligns with the rising point of the constellation Sagittarius as it appeared about 11,000 years ago, a position that occurs in late autumn. That timing corresponds with the seasonal pattern detected in the sediment analysis. The pillar is also positioned directly above the void identified by the radar scans, which some researchers believe was built to collect remains and fluids from bodies processed on the surface above.

Faunal analysis at the site has found an unusually high concentration of scavenger bird remains, including vultures and corvids, consistent with the idea that scavengers were deliberately attracted to the area.

Excavations in recent seasons have also found domestic structures near the ceremonial enclosures, with grinding stones and flint tools, indicating that people lived and worked at the site rather than visiting only for ceremonies.

Similar features have been identified at nearby sites, including Karahan Tepe, about 11 kilometers away, where excavators found a pillar carved with a human face and a statue depicting a deceased person with a sealed mouth. Another site, Sayburç, contains a human face carved into bedrock opposite a large niche. AI analysis of the symbolic systems across these sites found shared motifs related to death, vultures, headless figures, and skulls, while each site retained its own local style.

The scale of the practices remains uncertain. Researchers estimate that between 5,000 and 15,000 individuals may be represented in the subsurface deposits, based on fragment density in excavated areas and extrapolated across the total site area. That estimate suggests the site may have functioned as a regional mortuary center, where the dead were transported for ritual processing over many generations.

One notable pattern in the data is a decline in technical skill over time. The earliest skull modifications and pillar carvings show the highest precision, while later examples are shallower and less carefully executed. This pattern has led some researchers to suggest that the people who built the earliest structures inherited knowledge from an earlier culture rather than developing it themselves, and that later generations were attempting to maintain traditions they no longer fully understood.

The deliberate burial of the site around 8000 BCE has also been re-examined. Rather than being a ritual closure, the fill appears to have been placed carefully in layers that protected the structures beneath. This occurred around the time agriculture was becoming established in the region, when the hunter-gatherer way of life was ending.

The void beneath Enclosure D has not been excavated. The Turkish Ministry of Culture has classified the exact coordinates, and the research team has not publicly discussed plans to open the chamber. Secondary voids connected to the main space by carved channels have also been detected but remain unexplored.

The available evidence indicates that Göbekli Tepe was a mortuary site where bodies were processed in a systematic manner over a long period. The skulls were modified and displayed, the flesh was removed, and the remains were deposited in ways that suggest deliberate ritual practice. The site’s religious character, if it had one, was centered on death and the transformation of the dead.

What the builders believed about the afterlife, why the skulls were so important, and who was brought to the site for processing remain unknown. The radar data shows that most of the site is still underground, and the contents of the unopened chambers are unknown.