Pepys Island is a phantom island

Phantom island

Phantom islands are islands that were believed to exist, and appeared on maps for a period of time during recorded history, but were later removed after they were proved to be nonexistent...

, said to lie about 230 nmi (264.7 mi; 426 km) north of the Falkland Islands

Falkland Islands

The Falkland Islands are an archipelago in the South Atlantic Ocean, located about from the coast of mainland South America. The archipelago consists of East Falkland, West Falkland and 776 lesser islands. The capital, Stanley, is on East Falkland...

 in 47°S. It was first described by Ambrose Cowley

Ambrose Cowley

William Ambrosia Cowley was a 17th century English buccaneer who surveyed the Galápagos Islands during his circumnavigation of the world, and published the first chart of the islands in 1684...

 in 1684, presumably mistaking the coordinates of one of the Falkland Islands, and named by him for Samuel Pepys

Samuel Pepys

Samuel Pepys FRS, MP, JP, was an English naval administrator and Member of Parliament who is now most famous for the diary he kept for a decade while still a relatively young man...

, Secretary of the Admiralty. Other observers on the voyage, such as William Dampier

William Dampier

William Dampier was an English buccaneer, sea captain, author and scientific observer...

, did not record the island. The name was also applied to South Georgia (54°15′00"S 36°45′00"W).

Many expeditions attempted to locate the island during the eighteenth century. Some, including John Byron

John Byron

Vice Admiral The Hon. John Byron, RN was a Royal Navy officer. He was known as Foul-weather Jack because of his frequent bad luck with weather.-Early career:...

, identified it with the Falkland Islands, but others such as Louis-Antoine de Bougainville, Lord Anson and even Captain Cook continued searching until the 1780s, when Cowley's original journal was rediscovered and his mistake noticed.