Petra. Jordan. View of tourists walking through the narrow ravine known as the Siq, which gives a spectacular introduction and entrance to the ancient city. Formed by tectonic forces spilt the mountain in two, the Siq is 1200 metres long, up to 80 metres high in sections, and its narrowest point the wall are only two metres apart. The vast ancient rose red city of Petra is the ancient home of the Kingdom of Nabataeans who settled here there more than two thousand years ago.