Kiribati

A few of the islands are compact with fringing reefs, but most are atolls. The largest atoll (and one of the largest in the world) is Kiritimati (Christmas Island) in the Line group, which has a land area of 150 square miles (388 square km) and accounts for about one-half of the country's total. Kiritimati was used for U.S. and British nuclear testing in the 1960s; it now has a large coconut plantation