MacCarthy Island, officially named Janjanbureh Island and originally known as Lemain Island, is an island located approximately 170 miles (272 km) upriver from the mouth of the Gambia River, in eastern Gambia, in the Janjanbureh District. Located on the island is the second-largest town in the country, Janjanbureh, but on many maps it still appears by its European name of Georgetown. In addition to being a destination for some wildlife tourists, the island is also the home of Gambia's largest prison.