Tuvalu consists of nine separate islands, six of which are atolls and three are reef islands. Since an atoll typically consists of several islets, there is a total of more than 124 islands and islets. The three remaining islands are actually atolls, too, but they have a completely closed rim of dry land, with a lagoon that has no connection to the open sea or that may be drying up. Each island is surrounded by a coral reef. The islands of Tuvalu are spread out between the latitude of 5° to 10° south and longitude of 176° to 180°, west of the International Date Line.