The archaeological site of Al-Hajar (Mada’in Saleh) in the Kingdom of Saudi Arabia, Its first site to be included in the World Heritage List. In the past it was called the room, It is the largest preserved site of the Nabataean civilization south of Petra in Jordan. It contains huge, well-preserved tombs. Its decorated facades date back to the first century BC until the first century AD. The site is located 500 km southeast of Petra. It includes about 50 inscriptions from the pre-Nabataean era. And a number of cave drawings. The stone site bears a unique testimony to the Nabataean civilization. His 111 huge tombs (94 of which were decorated with decorations) are considered… and water wells, An exceptional example of the architectural achievements of the Nabataeans and their hydrological expertise.