Dammam is the capital of the Eastern Province of Saudi Arabia, the most oil-rich region in the world.[citation needed] The judicial and administrative bodies of the province and several government departments are located in the city. Dammam is the largest city in the Eastern Province, and the fifth largest in Saudi Arabia, after Riyadh, Jeddah, Mecca and Medina. It forms part of the Dammam Metropolitan Area; The Dammam metropolitan area, or greater Dammam, is the metropolitan area associated with the city of Ad Dammam, Eastern Province, and its suburbs. It is the area that is closely linked to the city through social, economic, and cultural ties. The Dammam metropolitan area: mainly known as greater Dammam, is the largest metropolitan area in the Eastern Province of Saudi Arabia formed by three main neighboring cities: Dammam, Dhahran, and Khobar these 3 respectable cities are sometimes referred to as the triplet cities. The metropolitan area of the triplet cities has an estimated population of 4,140,000 as of 2012. Greater Dammam also includes many other smaller cities such as: Al Qatif, Safwa, and Ras Tanura,form a population of 5,212,000 as of 2012.The city is growing at an exceptionally high rate of 12% a year,the fastest in Kingdom, Gulf Cooperation Council, and the Arab World. Dammam Metropolitan Area, and the rest of the Eastern Province, is served by the King Fahd International Airport, the largest airport in the world in terms of land area, about 20 km to the northwest of the city. Dammam's King Abdul Aziz Sea Port is the largest on the Persian Gulf. Its import-export traffic in is second only to Jeddah Seaport in the the Middle East and North Africa MENA
