The Old Exchange & Provost Dungeon, also known as the Custom House, and The Exchange, is a historic building at East Bay and Broad Streets in Charleston, South Carolina. Built in 1767–1771, it has served a variety of civic institutional functions, including notably as a prisoner of war facility operated by British forces during the American Revolutionary War. The building was designated a National Historic Landmark in 1973. It is now a museum operated by the Daughters of the American Revolution.