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
Nui (atoll) in the parliament. He served as the Minister of Finance and Economic Planning from 1996 until 1999, and Minister of Health from 2001 to 2006. Isaia Taeia Italeli was the Minister for Natural Resources at the time of his death in 2011. Pelenike Isaia became the second woman ever to have sat in the Parliament of Tuvalu, she became an MP in the by-election following the death of her husband - Isaia Taeia Italeli - and represented Nui until the Tuvaluan general election, 2015. Nui (atoll) Nui is an atoll and one of nine districts of the Pacific Ocean state