Kiritimati or Christmas Island is a Pacific Ocean atoll in the northern Line Islands and part of the Republic of Kiribati. It has a population of about 5,000 people (2005 census).
The island has the greatest land area of any coral atoll in the world: about 322 square kilometres (124 sq mi); its lagoon is about the same size. The atoll is about 150 km (93 mi) in perimeter, while the lagoon shoreline extends for over 48 km (30 mi). Christmas Island comprises over 70% of the total land area of Kiribati, a country encompassing 33 Pacific atolls and islands.
It lies 232 km (144 mi) north of the Equator, 6,700 km (4,200 mi) from Sydney, and 5,360 km (3,330 mi) from San Francisco. Christmas Island is in the world's farthest forward time zone, UTC+14, and Christmas Island is the first inhabited place on Earth to experience the New Year each year (see also Caroline Atoll, Kiribati). Despite being 1,530 miles (2,460 km) east of the 180 meridian, a 1995 realignment of the International Dateline by the Republic of Kiribati "moved" Christmas Island to west of the dateline.
Nuclear tests were conducted in the region around Christmas Island by the United Kingdom in the late 1950s, and by the United States in 1962. During these tests islanders were not evacuated. Subsequently British, New Zealand, and Fijian servicemen as well as local islanders have claimed to have suffered from exposure to the radiation from these blasts.
The entire island is a Wildlife Sanctuary; access to five particularly sensitive areas is restricted.