Oman, independent state in the Middle East, extending about 1,610 km (1,000 mi) along the south-eastern coast of the Arabian Peninsula, bordered on the north by the Gulf of Oman, on the east and south by the Arabian Sea, the south-west by the Republic of Yemen, the west by the Rub al'Khali (Empty Quarter) of Saudi Arabia, and to the north-west by the United Arab Emirates. The nation's territory also includes the northern tip of the strategic Ra's (Cape) Musandam, which juts between the Persian Gulf and the Gulf of Oman; this portion is separated from the rest of the nation by territory of the United Arab Emirates. The nation's interior boundaries are not demarcated. Oman has an area of about 212,457 sq km (82,030 sq mi). The capital is Masqat, also known as Muscat.