Mada'in Salih boasts one of Saudi Arabia's most important archaeological sites, which includes marvelous rock tombs. Most of the tombs were carved between 100 BC and 100 AD, during the period when Mada'in Salih was the second most important Nabatean kingdom after Petra (Jordan). In 1880, Charles Doughty 'discovered' the tombs.
Although the tombs at Mada'in Salih are not as spectacular as the ones in Petra, they are much better preserved, since the rock they were carved from is much harder than the rock in Petra. The largest of the tombs in Mada'in Salih is the spectacular Qasr Farid. It was carved out of a single, standing-alone rock in the desert. The Diwan (meeting room) was carved into a hillside and might have been used as a cult site. Qasr al-Bint (the Girl's Palace) is a collection of tombs carved into a rocky outcrop.
The only feasable way to visit the ruins is with your own, or rented vehicle, as distances between them are large and the desert heat can be extreme. Organized tours are available from Medina and Riyadh. Mada'in Salih is some 900 km northwest of Riyadh and many roads in the region are not signposted.