volcanic Pacific island in the Lau Group of Fiji, South Pacific Ocean. It is 22 square miles (57 square km) in area, rises to 720 feet (220 metres), and was the site, in 1835, of Fiji's first Wesleyan missionary settlement (1835). The Lakemba Passage separates Lakeba from the islets of Nayau and Tuvuca (Tuvutha) to the north.