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,
Falkie Atoll Falkie Atoll Falkie Atoll is a small atoll within the nation of Solomon Islands, at . It is sometimes referred to as Van Ren Atoll, named after the Dutch explorer Jale Van Ren who discovered the atoll in 1679. Local name of this atoll is Kaka. Administratively, Falkie Atoll belongs to the Choiseul Province of Solomon Islands. It is the westernmost atoll in the Solomon Islands archipelago, 40 km northwest of Shortland Islands. However, the closest land is Bougainville, which is an autonomous region of Papua New Guinea. Its total land area is , but it encloses a lagoon of