It is one of the largest fortresses in the Americas and was designated by the United Nations Educational, Scientific and Cultural Organization (UNESCO) as a World Heritage Site in 1982—along with the nearby Sans-Souci Palace. The mountaintop fortress has itself become an icon of Haiti. The Citadel was built by Henri Christophe, a key leader during the Haitian slave rebellion (1791–1804),[2] after Haiti gained independence from France at the beginning of the 19th century.[3]