Chuuk Lagoon, previously Truk Atoll, is an atoll in the central Pacific. It lies about northeast of New Guinea, and is part of Chuuk State within the Federated States of Micronesia (FSM). A protective reef, around, encloses a natural harbour , with an area of . It has a land area of , with a population of 36,158 people and a maximal elevation of . Weno city on Moen Island functions as both the atoll's capital and the state capital, and is the largest city in the FSM with its 13,700 people. Chuuk Lagoon was the Empire of Japan's main naval base in the South Pacific theatre during World War II. It was the site of a major U.S. attack during Operation Hailstone in February 1944, and Operation Inmate, a small assault conducted by British and Canadian forces during June 1945. Name Chuuk means mountain in the Chuukese language. The lagoon was known mainly as Truk (a mispronunciation of Ruk), until 1990. Other names included Hogoleu, Torres, Ugulat, and Lugulus. Geography Chuuk Lagoon is part of the larger Caroline Islands group. The area consists of eleven major islands (corresponding to the eleven municipalities of Truk lagoon, which are Tol, Udot, Fala-Beguets, Romanum, and Eot of Faichuk group, and Weno, Fefen, Dublon, Uman, Param, and Tsis of Namoneas group) and forty-six smaller ones within the lagoon, plus forty-one on the fringing coral reef, and is known today as the Chuuk islands, part of the Federated States of Micronesia in the Pacific Ocean. Table of main islands This is the following list of islands, villages and population following the 2010 census: Climate History Prehistory It is not known when the islands of Chuuk were first settled, but archaeological evidence indicates that islands of Feefen and Wééné Islands had human settlements in the first and second century BC. Later evidence indicates that widespread human settlements appeared in Chuuk during the 14th century AD. Colonialism The first recorded sighting by Europeans was made by Spanish navigator Álvaro de Saavedra on board of the ship Florida during August or September 1528. They were later visited by Spaniard Alonso de Arellano on 15 January 1565 on board of galleon patache San Lucas. As part of the Caroline Islands, Truk was claimed by the Spanish Empire, which made an effort to control the islands in the late 19th century. Chuuk lagoon was then inhabited by several tribes