Millennium Island

Caroline Island, or Caroline atoll, is an atoll, in the Pacific Ocean that is part of Kiribati. It is the easternomost atoll of Kiribati. The atoll is part of the Southern Line Islands. In total, the atoll consists of 39 islets(motus), which cover a surface (landmass) of about . The atoll covers an area of about 
It was first sighted by Europeans in 1606, it was claimed by the United Kingdom in 1868. It has been part of the Republic of Kiribati since the island nation's independence in 1979. Caroline Island has remained relatively untouched and is considered one of the world's most pristine tropical islands, despite guano mining, copra harvesting, and human habitation in the 19th and 20th centuries. It is home to one of the world's largest populations of the coconut crab and is an important breeding site for seabirds, most notably the sooty tern.
The atoll is currently designated as a wildlife sanctuary. In 2014 the Kiribati government established a 12-nautical-mile fishing exclusion zone around each of the southern Line Islands (Caroline (commonly called Millennium), Flint, Vostok, Malden, and Starbuck). Both Flint and wostok are about to the west. Papeete, Thahiti is about to the south.
Geography.
It extends about from north to south, and about from east to west. The total landmass is just . The coral reef extends about out. The lagoon is very shallow, and normal boats usually cannot enter. At high tide, it is possible to reach a beach with a boat. At low tide, a walk of about in waist-deep water is required.
In the north and in the south, there are bigger islands. The one in the north is called Nake Island, the one in the south is called South Island. Both have freshwater sources. There are aquifers on both. 
In 1994, Kiribati changed the International date line, so that all of Kiribati would have the same date. This meant that Caroline atoll would be the first landmass on earth with the new date. For the year-2000 celebrations, the atoll was renamed Millennium Island. Other names in the past have included "Hirst Island", "Clark Island" "and Independence Island".
The island is an important breeding place for birds. The only known mammal on the atoll is a rat.