Sites with similar ‘T’-shaped pillars from the Pre-Pottery Neolithic (PPN). Photo by Arekrishna (2017). CC BY-SA 4.0. Source: “Göbekli Tepe” (2020). In: Wikipedia. The Free Encyclopedia. May 13, 2020 800 × 592 Sites with similar ‘T’-shaped pillars from the Pre-Pottery Neolithic (PPN). Photo by Arekrishna (2017). CC BY-SA 4.0. Source: “Göbekli Tepe” (2020). In: Wikipedia. The Free Encyclopedia.