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). Saudi Arabia is the fourth-largest Asian country by area, the largest in Western Asia, and the second-largest in the Arab world. It is bordered by Jordan, Iraq, and Kuwait to the north, the Persian Gulf, Qatar, and the United Arab Emirates to the east, Oman to the southeast, Yemen to the south, and the Red Sea to west. Bahrain is an island country off the east coast. In the northwest, the Gulf of Aqaba, which measures 24 km (15 mi) at its widest point, separates Saudi Arabia from Egypt. Saudi Arabia 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.