Saudi Arabia is divided into 13 provinces, each with its own capital city. The provinces are: Northern Border, Jouf, Tabuk, Hail, Qasim, Madinah, Makkah (Mecca), Riyadh, Eastern Province, Baha, Asir, Jizan, and Najran. The Kingdom of Saudi Arabia occupies the largest land area in the Middle East and may be divided into seven geographical regions regarding the physical features: The Empty Quarter (Al-
Rub Al Khali) desert, The Western highlands, The Northern Mountains and plateaus, Widespread Mountain and desert valleys, The Eastern plateaus and plains, The "Najd" plateaus, Central Region, The "Tihama" plains, South West region.
The Arabian platform is generally mountainous, with its highest part in the extreme west, along the Red Sea, sloping gradually eastward to the Persian Gulf. These mountainous region is known as Hejaz in the north and Asir in the south. The peaks rise abruptly from a narrow coastal plain to heights of more than 3,000 m. Jabal Sawda (the Black Mountain) is Saudi Arabia's highest elevation at 3,100 meters. East of the mountains lies the Nejd, a high central plateau with a relatively level surface. The lowlands in the country are located close to the Persian Gulf.
Saudi Arabia is the seat of the largest sand-mass in the world. Three of Saudi Arabia's largest and most barren deserts are: the Nefud in the north, the Dahna in the east, and the Rub al Khali (Empty Quarter) in the south. The Rub al Khali covers an area about the size of Texas and is an almost continuous body of sand. There are no rivers or large standing bodies of water