Chuuk Lagoon (formerly Truk Lagoon) is a sheltered body of water in the central Pacific, about 1,800 km north-east of New Guinea. It is part of Chuuk State within the Federated States of Micronesia. The atoll enclosing the lagoon consists of a protective reef, 225 km (140 mi) around, forming a natural harbor 79 by 50 km (49 by 30 mi), with an area of 2,130 sq km (820 sq mi). It has a land area of some 127 square km (49 sq mi). Image courtesy of NASA.