Ailuk Atoll (Marshallese: Aelok, [ɑ̯ɑ͡æe̯elʲe͡okʷ]) is a coral atoll of 57 islets in the Pacific Ocean, and forms a legislative district of the Ratak Chain of the Marshall Islands. It is located approximately 72 kilometres (45 mi) north from Wotje. Its total land area is only 5.4 square kilometres (2.1 sq mi), but it encloses a lagoon with an area of 177.45 square kilometres (68.51 sq mi). The major islets are: Ajelep, Aliej, Ailuk, Alkilwe, Barorkan, Biken, Enejabrok, Enejelar, Kapen and Marib. Most of the islets are on the eastern side of the atoll. The western and southern sides of the atoll have a nearly continuous submerged coral reef, with three main passes that lead in to the lagoon: Erappu Channel, Marok Channel and Eneneman Channel on the west side.