The United Arab Emirates is situated in Middle East/southwest Asia, bordering the Gulf of Oman and the Persian Gulf, between Oman and Saudi Arabia; it is on a strategic location along northern approaches to the Strait of Hormuz, a vital transit point for world crude oil. The UAE lies between 22°50′ and 26° north latitude and between 51° and 56°25′ east longitude. It shares a 19-kilometer border with Qatar on the northwest (according to the UAE), a 530-kilometer border with Saudi Arabia on the west, south, and southeast, and a 450-kilometer border with Oman on the southeast and northeast. The land border with Qatar in the Khawr al Udayd area is a source of ongoing dispute (in fact, whether it even shares a land border with Qatar is in dispute). The total area of the UAE is approximately 83,600 square kilometers. The country's exact size is unknown because of disputed claims to several islands in the Persian Gulf, because of the lack of precise information on the size of many of these islands, and because most of its land boundaries, especially with Saudi Arabia, remain undemarcated. The largest emirate, Abu Dhabi, accounts for 87 percent of the UAE's total area (67,340 square kilometers).