peninsula, northeastern extension of the Arabian Peninsula, separating the Gulf of Oman on the east from the Persian Gulf on the west to form the Strait of Hormuz to the north. The Ruʾūs al-Jibāl (the Mountaintops), the northernmost extremity of the al-Gharbī al-Ḥajar (Western Hajar mountains), occupy the northern tip of the Musandam Peninsula; this area is a part of Oman, and is separated from the rest of the country (to the south) by the United Arab Emirates. The peninsula is generally about 22 mi (35 km) wide. The Khawr (channel) ash-Shamm (also called Elphinstone Inlet) and the Ghubbat (bay) al-Ghazīrah (Malcom Inlet) deeply incise the coastline from west and east a few miles south of the Strait of Hormuz and come within several hundred yards of bisecting the peninsula. The Khawr ash-Shamm is about 10 mi long and is bordered by cliffs that rise to heights of 3,000 to 4,000 ft (900 to 1,200 m). The highest elevation on the mountainous peninsula is 6,847 ft at Jabal (mount) al-Ḥartīm. The mountains slope steeply seaward forming an extremely rugged and rocky coast that makes Musandam a hazard to navigation. Wadi beds, where sporadic rains have carved deep ravines, are fertile with vegetation and the lower mountain slopes are covered with wild olive trees; juniper trees grow at the summits. Dates and vegetables are the main crops on the peninsula.

The peninsula is mainly inhabited by the Shihuh, who are fishermen and herdsmen and are probably descended from the original inhabitants of northern Oman, pushed into the mountains by successive Muslim and Portuguese invasions. Fishing is the peninsula's main industry with packing plants at al-Khaṣab and Bayʿah. There are reserves of petroleum off the western coast of the Musandam Peninsula. Communication is mostly by sea, since no roads cross the forbidding terrain. The Sultanate of Oman has created the Musandam Development Committee for building fishing jetties, construction of the Khaṣab dam and food storage, and undertaking the Bayʿah power expansion project during the Second Development Plan (1981–85). The main population centre is the oasis town of Dibā on the peninsula's southeastern coast.