Washington, D.C., formally the District of Columbia and commonly referred to as D.C.; Washington; or The District, is the capital of the United States. Washington, D.C. is located in the mid-Atlantic region of the U.S. East Coast. The District is bordered by Montgomery County, Maryland to the northwest; Prince George's County, Maryland to the east; Arlington County, Virginia to the south; and Alexandria, Virginia to the west. Washington, D.C. is a planned city. The architecture of Washington varies greatly. Six of the top 10 buildings in the American Institute of Architects' 2007 ranking of "America's Favorite Architecture" are in the District of Columbia: the White House, the Washington National Cathedral, the Thomas Jefferson Memorial, the United States Capitol, the Lincoln Memorial, and the Vietnam Veterans Memorial. The neoclassical, Georgian, gothic, and modern architectural styles are all reflected among those six structures and many other prominent edifices in Washington.
Washington has a growing, diversified economy with an increasing percentage of professional and business service jobs. The District's gross state product in 2018-Q2 was $141 billion. The Washington Metropolitan Area's gross product was $435 billion in 2014, making it the sixth-largest metropolitan economy in the United States. Tourism is Washington's second-largest industry. Approximately 18.9 million visitors contributed an estimated $4.8 billion to the local economy in 2012. The District also hosts nearly 200 foreign embassies and international organizations such as the World Bank, the International Monetary Fund (IMF), the Organization of American States, the Inter-American Development Bank, and the Pan American Health Organization. In 2008, the foreign diplomatic corps in Washington employed about 10,000 people and contributed an estimated $400 million annually to the local economy.