Mount Pleasant is a large suburban town in Charleston County, South Carolina, United States. In the Lowcountry, it is the fourth-most populous municipality in South Carolina, and for several years was one of the state's fastest-growing areas, doubling in population between 1990 and 2000. The population was 90,801 at the 2020 census. It is part of the Charleston metropolitan area. At the foot of the Arthur Ravenel Bridge is Patriots Point, a naval and maritime museum, home to the World War II aircraft carrier USS Yorktown, which is now a museum ship. The Ravenel Bridge, an eight-lane highway that is part of U.S. Route 17 and was completed in 2005, spans the Cooper River and links Mount Pleasant with the city of Charleston.