Christmas Island (officially called the Republic of Kiribati), is an island nation in the central tropical Pacific Ocean, the largest coral atoll in the world with an area of 248 square miles of which 125 square miles is land and the remainder lagoon.The nation is composed of 32 atolls and one raised coral island, Banaba, dispersed over 1,351,000 square miles straddling the equator, and bordering the International Date Line at its easternmost point.The name Kiribati is the local pronunciation of Gilberts, which derives from the main island chain, named the Gilbert Islands after the British explorer Thomas Gilbert, who was the first European to discover them. The capital, South Tarawa, consists of a number of islets connected through a series of causeways, located in the Tarawa archipelago. Kiribati became independent from the United Kingdom in 1979. It is a member of the Commonwealth of Nations, the IMF and the World Bank, and became a full member of the United Nations in 1999.The entire island is a Wildlife Sanctuary; the flora and the fauna are unique, but the island is affected by regular, severe droughts. Most of the atoll's food supplies have to be imported, although marine fish are plentiful. Exports of the atoll include aquarium fish, coconuts, and seaweed. Additionally, there is a small amount of tourism.