Congaree Swamp National Monument, 20 miles southeast of Columbia and just north of Lake Marion on the Congaree River, is more a floodplain than a swamp. Its 22,000 acres include six bald cypresses believed to be the largest in the nation; in what is the largest tract of old growth bottomland hardwoods.

More than 90 species of trees have been identified in the Congaree Swamp, and half the preserve has never been logged. A boardwalk, five hiking trails ranging from 1 to 10 miles, and canoeing routes make the Congaree accessible to visitors, and more than 94,000 a year, including scientists from around the world, tour the unique ecosystem. In 1983, the United Nations designated the swamp an International Biosphere Reserve.