Many of these pillars are decorated with anthropomorphic details, clothing, and sculptural reliefs of wild animals, providing archaeologists rare insights into prehistoric religion and the particular iconography of the period.

The 15 m (50 ft) high, 8 ha (20-acre) tell is densely covered with ancient domestic structures[6] and other small buildings, quarries, and stone-cut cisterns from the Neolithic, as well as some traces of activity from later periods.

Göbekli Tepe, a monumental complex built on the top of a rocky mountaintop, with no clear evidence of agricultural cultivation, has played a prominent role in this debate.

Recent findings suggest that there was a settlement at Göbekli Tepe, with domestic structures, extensive processing of cereals, a water supply, and tools associated with daily life.

After his death in 2014, work continued as a joint project of Istanbul University, Şanlıurfa Museum, and the German Archaeological Institute, under the direction of Turkish prehistorian Necmi Karul.

Göbekli Tepe was designated a UNESCO World Heritage Site in 2018, recognising its outstanding universal value as "one of the first manifestations of human-made monumental architecture".

[26] Excavations have taken place at the southern slope of the tell, south, and west of a mulberry that marks an Islamic pilgrimage,[27] but archaeological finds come from the entire plateau.

[38] Evidence indicates the inhabitants of Göbekli Tepe were hunter-gatherers who supplemented their diet with early forms of domesticated cereal and lived in villages for at least part of the year.

[46] Radiocarbon dating shows that the earliest exposed structures at Göbekli Tepe were built between 9500 and 9000 BCE, towards the end of the Pre-Pottery Neolithic A (PPNA) period.

[51][52][9] Subsequent research led to a significant revision of Schmidt's chronology, including the abandonment of the hypothesis that the fill of the structures was brought from elsewhere, and a recognition that direct dates on plaster are affected by the old wood effect.

It details the history of the large circular enclosures, including events that led to their alteration or abandonment, and the evolution of the domestic buildings surrounding them.

The reliefs depict mammals such as lions, bulls, boars, foxes, gazelle, and donkeys; snakes and other reptiles; arthropods such as insects and arachnids; and birds, particularly vultures.

[citation needed] Some of the floors in this, the oldest, layer are made of terrazzo (burnt lime); others are bedrock from which pedestals to hold the large pair of central pillars were carved in high relief.

[66] The enclosures, lying over 10 metres (33 ft) below the highest areas of the settlement, were subject to several slope slide events during the occupation period of Göbekli Tepe.

These measures, however, proved futile, when a second major slope slide probably caused the enclosure to the abandoned during Building Phase 6, around the late 9th millennium BCE.

[68] In the earliest occupation phase, round-oval domestic structures were built alongside the large enclosures, which indicate a (semi) sedentary lifestyle.

The advent of agriculture and animal husbandry brought new realities to human life in the area, and the "Stone-age zoo" apparently lost whatever significance it had had for the region's older, foraging communities.

Schmidt maintained that "the work of quarrying, transporting, and erecting tons of heavy, monolithic, and almost universally well-prepared limestone pillars [...] was not within the capability of a few people".

[26] Experiments at Göbekli Tepe itself have suggested that all the PPNB structures currently exposed could have been built by 12–24 people in less than four months, allowing for time spent quarrying stone and gathering, and preparing food.

The sex of the individuals depicted cannot be clearly identified, though Schmidt suggested that they are two men because the belts they wear are a male attribute in the period.

[citation needed] Butchered bones found in large numbers from the local game such as deer, gazelle, pigs, and geese have been identified as refuse from food hunted and cooked or otherwise prepared for the congregants.

[96] Zooarchaeological analysis shows that gazelle were only seasonally present in the region, suggesting that events such as rituals and feasts were likely timed to occur during periods when game availability was at its peak.

He presumed shamanic practices and suggested that the T-shaped pillars represent human forms, perhaps ancestors, whereas he saw a fully articulated belief in deities as not developing until later, in Mesopotamia, that was associated with extensive temples and palaces.

[102] According to Rémi Hadad, in recent years "the interpretative enthusiasm that sought to see Göbekli Tepe as a regional ceremonial centre where nomadic populations would periodically converge is giving way to a vision that is more in line with what is known about other large Pre-Pottery Neolithic sites, where ritual and profane functions coexist.

[106] American archaeologist Peter Benedict identified the stone tools collected from the surface of site as characteristic of the Aceramic Neolithic,[107] but mistook the upper parts of the T-shaped pillars for grave markers.

[108] The hill had long been under agricultural cultivation, and generations of local inhabitants had frequently moved rocks and placed them in clearance piles, which may have disturbed the upper layers of the site.

[69] In October 1994, German archaeologist Klaus Schmidt, who had previously been working at Nevalı Çori, was looking for evidence of similar sites in the area and decided to re-examine the location described by the Chicago researchers in 1963.

[69][109] Asking in nearby villages about hills with flint,[109] he was guided to Göbekli Tepe by Mahmut Yıldız, whose family owned the land the site was situated on.

[105][110] Having found similar structures at Nevalı Çori, Schmidt recognized the possibility that the stone slabs were not grave markers as supposed by Benedict, but the tops of prehistoric megaliths.

[114] Göbekli Tepe was designated a UNESCO World Heritage Site in 2018, recognising its outstanding universal value as "one of the first manifestations of human-made monumental architecture".