Palmerston Island is one of a number of sandy islets on a continuous ring of coral reef enclosing a lagoon. The largest of the islets include Palmerston, North Island, Lee To Us, Leicester, Primrose, Toms, and Cooks. The total land area of the islets is approximately 1 square mile (2.6 km). The coral reef covers about 3,600 acres (15 km). The lagoon is some 7 miles (11 km) across, covering an area of 56 square kilometres (22 sq mi). There are several small passages through the reef for boats, though there is no safe entry for large ships. At a latitude of 18 degrees south, Palmerston enjoys a tropical climate but is exposed to severe tropical cyclones. A particularly destructive series of storms occurred during the 1920s and 1930s.

Palmerston was recorded by Captain Cook in 1774, but he did not land on the island until 13 April 1777. He found it uninhabited, though some ancient graves were discovered. Cook named the island after Henry Temple, 2nd Viscount Palmerston, then Lord of the Admiralty. The ancient name of the island was supposedly Avarau, meaning "two hundred harbour entrances". In 1863 William Marsters, a ship's carpenter and barrel maker, arrived on Palmerston from Manuae with two Polynesian wives. He added a third wife and sired a large family of some 23 children, whose descendants now inhabit Palmerston. Thus, Palmerston Island is the only island in the Cook Islands for which English is the native language.

When someday comes you'll need to get in.

When someday comes you'll need to be able to get around.