Saudi Arabia, officially Kingdom of Saudi Arabia, kingdom (2005 est. pop. 26,419,000), 829,995 sq mi (2,149,690 sq km), comprising most of the Arabian peninsula. It is bounded on the west by the Gulf of Aqaba and the Red Sea; on the east by the Persian Gulf, Qatar, and the United Arab Emirates; on the south by Yemen and Oman; and on the north by Jordan, Iraq, and Kuwait. Saudi Arabia formerly shared a neutral zone with Iraq and another with Kuwait; both are now divided between the countries. Riyadh is the capital and largest city.