The Arabian Peninsula and Gulf States

The Arabian Peninsula, bounded by the Red Sea to the west, the Arabian Sea and Gulf of Aden to the south, and the Persian Gulf to the east, is dominated physically by the Rub' al Khali, or Empty Quarter, the largest contiguous sand desert in the world, covering roughly 650,000 square kilometers across Saudi Arabia, Oman, the United Arab Emirates, and Yemen. The peninsula's interior plateau, the Najd, rises to mountain ranges along its western and southern edges, including the Hejaz and Asir mountains bordering the Red Sea, which capture enough seasonal monsoon moisture to support terraced agriculture in parts of Yemen and southwestern Saudi Arabia, in sharp contrast to the hyper-arid interior. Historically, the peninsula's population was concentrated in oasis towns, such as Mecca and Medina in the Hejaz, and along the coasts, where Bedouin pastoral nomadism and Indian Ocean maritime trade, including the historic pearling industry of the Gulf coast, sustained settlement long before the discovery of oil.