Manra Island or Sydney Island, is one of the Phoenix Islands in the Republic of Kiribati. It lies at . longitude, and has an area of 4.4 km2. and an elevation of approximately six meters. Together with the seven other Phoenix Islands, it forms part of the Phoenix Islands Protected Area, the world's largest marine protected area. Charles Darwin visited the island during his five-year voyage (1831-1836), following which in 1842 he published an explanation for the creation of coral atolls in the South Pacific.