Atoll of an atoll is very small in comparison to the total area. Atoll islands are low lying, with their elevations less than 5 meters (9). Measured by total area, Lifou (1146 km²) is the largest raised coral atoll of the world, followed by Rennell Island (660 km²). More sources however list as the largest atoll in the world in terms of land area Kiritimati, which is also a raised coral atoll (321.37 km² land area; according to other sources even 575 km²), 160 km² main lagoon, 168 km² other lagoons (according to other sources 319 km² total lagoon size). The
Haa Alif Atoll Secretariat of North Thiladhunmathi Atoll Council is located. The Northern Thiladhunmathi Atoll administrative division consists of a total of 43 islands spread over two natural geographic atolls, namely Northern Thiladhunmathi, and Ihavandhippolhu. Northern Thiladhunmathi is the northern-most portion of the huge Thiladhunmathi Atoll. Thiladhunmathi Atoll was administratively divided into northern and southern divisions in 1958. Ihavandhippolhu lies to the north of Northern Thiladhunmathi, with the Ihavandhoo Kandu channel separating the two, and is the northern-most atoll of the Maldives. It is a small natural atoll 22 km in length. It has 25 islands lying all around the boundary reef. One