The shape of the pillars
The most distinctive features of Gobekli Tepe are its tall pillars of limestone, each shaped like a capital letter T. The upright shaft is rectangular in section and the broad crosspiece sits at the top. They stand in circles, with two taller pillars at the centre of each of the large enclosures and a ring of shorter ones set into the surrounding wall.
The biggest known examples are about 5 to 5.5 metres high, and are usually estimated to weigh in the order of 10 tonnes, although figures vary between reports and should be treated as approximate. The pillars of the outer rings are shorter and lighter. Most are made of the pale limestone that forms the plateau itself, so the stone did not have to be transported from far away.
Pillars with human features
What makes the T-shaped pillars striking is that many of them carry carved details that make them look like stylised people. On several of the central pillars, long arms are carved in low relief down the narrow sides, with the hands reaching toward the front, where the fingers meet over what would be the belly. Some have a belt carved across the shaft, and below it a decorated loincloth or pelt, in places shown as the skin of an animal, with details that resemble a fox pelt.
The flat top of the T is generally taken to be the head, but the heads carry no faces. Schmidt, who directed the excavation, therefore described them as abstract, non-realistic beings, possibly the ancestors or powerful figures of the builders’ beliefs. Others have suggested they represent people, spirits or supernatural beings. Which of these is right is not settled, and the choice of the human form without a face is part of why the site continues to be discussed.
The pairs of tall central pillars in the large enclosures are often compared to a pair of individuals standing in the middle, facing the surrounding ring of smaller pillars, which look inward as if they were a gathering. This is an interpretation of the arrangement, not a fact recorded by the builders.
Quarrying
The builders did not have metal; copper working and the bronze alloying that later made metal tools common were still thousands of years away. They used stone tools, mostly flint, and probably wooden and bone tools. Several quarries lie on the plateau near the enclosures. In them, researchers have found pillar blanks still attached to bedrock or lying unfinished. One unfinished pillar in a quarry is reported to be about 7 metres long, longer than any erected pillar so far found, although the exact figure should be checked against the latest publications.
The likely method, as reconstructed from the evidence in the quarries, was to cut deep channels around a block in the natural limestone with flint picks, then lever or wedge it free from below. The surface was then shaped with stone tools and polished by rubbing or pounding with harder stones. Limestone is relatively soft and splits along natural bedding planes, which makes it a practical material for this kind of work, though the labour was still large.
Moving and raising
Moving a multi-tonne pillar from the quarry to the enclosure over a short distance would have required many people, and probably ropes, wooden rollers or sledges, and ramps. No ancient ropes or sledges survive, so this is an informed reconstruction, a point also true of the debates around moai transport methods on Easter Island, where the details are likewise argued. At Gobekli Tepe the quarries are close, within a few hundred metres, which made the task more manageable.
Many of the central pillars were set into sockets cut into the bedrock, or into pedestals shaped from it. Dry-stone and clay-bound rubble walls and stone benches were then built between the pillars of the outer ring. The result suggests a design drawn up in advance: the pillars are carefully oriented in relation to each other, and the whole layout appears planned, not accidental. Parallel carving traditions of a much later date, such as the shaping of statues in the Rano Raraku quarry, show how a single quarry can supply a ritual landscape, but there is no known link between the traditions.
Decoration
Besides the human features, many pillars have relief or incised carving of animals and abstract symbols. Common signs include H-shapes, crescents and discs, and these are generally regarded as symbols whose meaning is not known. The animal carvings, which include snakes, foxes, boars, cranes and other creatures, have their own article. Some pillars have no decoration at all, which makes the carved ones stand out.
The carving was mostly done in relief by scraping or pecking away the surrounding surface, leaving the design standing out, though a few animals are freestanding or nearly so. Traces of paint have not been convincingly documented, and statements that the pillars were once brightly painted should be treated as speculation unless supported by analysis.
What the pillars show
The pillars matter because they show what people without farms, towns or metals were able to achieve. Cutting, shaping and raising dozens of multi-tonne blocks implies leaders or organisers, or at least a strong shared purpose, and a body of craft knowledge handed from one generation to the next. Estimates of the numbers of people involved are guesses at present. Because only a small part of the site has been excavated, the full number and range of the pillars is not yet known, and new discoveries may change the picture.