Ad-Dahna Desert passages which can be several kilometers long. Local Bedouin have always known these caves and some were used as water supplies. They were first systematically studied in the 1981, and later explored and reported by the Saudi Geological Survey. Ad-Dahna Desert The ad-Dahna Desert is the central division of the Arabian Desert. It is a corridor of sandy terrain forming a bow-like shape that connects an-Nafud desert in the north to Rub' al-Khali desert in the south. Its length is more than 1,000 km siding Twaik Mountains from the east and does not exceed 80 km in width. It is
Geography of Saudi Arabia Stretching more than 125 kilometers south from the An Nafud in a narrow arc is the ad-Dahna desert, a narrow band of sand mountains also called the river of sand. Like the An Nafud, its sand tends to be reddish, particularly in the north, where it shares with the An Nafud the longitudinal structure of sand dunes. The Ad Dahna also furnishes the Bedouin with winter and spring pasture, although water is scarcer than in the An Nafud. The southern portion of the Ad Dahna curves westward following the arc of the Jabal Tuwayq. At its southern end, it merges