The Kingdom of Saudi Arabia is the largest country in the Middle East by land area and constituting the bulk of the Arabian Peninsula. It is bordered by Jordan and Iraq on the north and northeast, Kuwait, Qatar and the United Arab Emirates on the east, Oman on the southeast, and Yemen on the south. It is also connected to Bahrain by the King Fahd Causeway. The Persian Gulf lies to the northeast and the Red Sea to its west. Saudi Arabia has an estimated population of 25.7 million of which 5.5 million are non-citizens, and its size is approximately 2,149,690 square kilometres (830,000 sq mi). The kingdom is sometimes called "The Land of the Two Holy Mosques" in reference to Mecca and Medina, the two holiest places in Islam. The two mosques are Masjid al-Haram (in Mecca), and Al-Masjid al-Nabawi (in Medina). Saudi Arabia has the world's largest oil reserves and is the world's largest oil exporter. Oil accounts for more than 90% of exports and nearly 75% of government revenues, facilitating the creation of a welfare state.