The tell or artificial mound has a height of and is about in diameter, approximately above sea level. It includes two phases of use, believed to be of a social or ritual nature by site discoverer and excavator Klaus Schmidt, dating back to the 10th–8th millennium BCE. During the first phase, belonging to the Pre-Pottery Neolithic A (PPNA), circles of massive T-shaped stone pillars were erected—the world's oldest known megaliths. Dated at around 9,500 BCE, these megaliths are 5,500 years older than the first cities of Mesopotamia and 7,000 years older than Stonehenge.