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 Alif Atoll Dhaalu Atoll. The North Ari Atoll administrative division consists of the northern part of the geographic or natural atoll Ari Atoll (described as Northern Ari Atoll in this context to differentiate from the official name of the administrative division), Rasdhukuramathi Atoll and Thoddoo Island. The atolls consists of Inhabited Islands and Uninhabited Island, a definition which includes resort islands, airport islands and industrial islands. Maalhos: Maalhos is geographically the westernmost island of the Atoll and the second-most westerly inhabited island of the Maldives after Maamakunudhoo). Vajrayana Buddhist remains have been found on this island. Rasdhoo: Rasdhoo is the capital island