Atoll remains of an ancient atoll as a hill in a limestone area is called a reef knoll. The second largest atoll by dry land area is Aldabra with 155 km². The largest atoll in terms of island numbers is Huvadhu Atoll in the south of the Maldives with 255 islands. In 1842, Charles Darwin explained the creation of coral atolls in the southern Pacific Ocean based upon observations made during a five-year voyage aboard from 1831 to 1836. Accepted as basically correct, his explanation involved considering that several tropical island types—from high volcanic island, through barrier reef island, to atoll—represented
Providence Atoll Providence Atoll The Providence Atoll is part of the Farquhar Group of islands in the Seychelles that are part of the Outer Islands, with a distance of southwest of the capital, Victoria, on Mahé Island. The atoll was discovered in 1501 by Joao da Nova, a Portuguese explorer. The atoll was under British control until 1976 when they became part of Seychelles at the time of independence. Providence got its name after an event which happened in 1763. A French frigate, ”Heureuse” , was stranded on its reef, 705 km from Victoria near the northern end of the atoll. The