Saudi Arabia,[c] officially the Kingdom of Saudi Arabia (KSA),[d] is a country in Western Asia. It spans the vast majority of the Arabian Peninsula, with a land area of approximately 2,150,000 km2 (830,000 sq mi). It is the fourth-largest country entirely in Asia, the largest in Western Asia, and the second-largest in the Arab world. It is bordered by the Red Sea to the west, Jordan, Iraq, and Kuwait to the north, the Persian Gulf, Qatar, and the United Arab Emirates to the east, Oman to the southeast, and Yemen to the south. Bahrain is an island country off the east coast. The Gulf of Aqaba in the northwest, whose maximum width is 24 km (15 mi), separates it from Egypt. It is the only country with a coastline along both the Red Sea and the Persian Gulf, and most of its terrain consists of arid desert, lowland, steppe, and mountains. Its capital and largest city is Riyadh. The country is home to Mecca and Medina, the two holiest cities in Islam.
The area of modern-day Arabia formerly consisted of mainly four distinct historical regions: Hejaz, Najd, and parts of Eastern Arabia (Al-Ahsa) and Southern Arabia (‘Asir).
