Atoll Atoll An atoll (, , , , or ), sometimes called a coral atoll, is a ring-shaped coral reef including a coral rim that encircles a lagoon partially or completely. There may be coral islands or cays on the rim. The coral of the atoll often sits atop the rim of an extinct seamount or volcano which has eroded or subsided partially beneath the water. The lagoon forms over the volcanic crater or caldera while the higher rim remains above water(s) or at shallow depths that permit the coral to grow and form the reefs. For the atoll to persist,
Alif Dhaal Atoll found in Ariadhoo Island. Whale sharks are year-round residents of Alif Dhaal Atoll. The South Ari Atoll administrative division consists of the southern part of the geographic or natural Ari Atoll (described as Southern Ari Atoll in this context to differentiate from the official name of the administrative division). The atoll consists of Inhabited Islands and Uninhabited Island, a definition which includes resort islands, airport islands and industrial islands. Resort islands are classified as Uninhabited Islands which have been converted to become resorts. The following are the resort islands, with the official name of the resort. Alif Dhaal Atoll Alifu