A phantom island is an island that was shown on maps but was later found not to exist. These islands often come from the reports of sailors who explored new areas. They can be the result of mistakes in navigation, incorrect observations, unconfirmed false information, or intentional lies. Some phantom islands remained on maps for many years before being proven not to exist. Unlike lost lands, which are said to have existed but were destroyed by the sea or other events, phantom islands are claimed to exist at the same time but are later found not to exist or are discovered not to be islands, such as the Island of California.

Examples

Some islands may have been entirely mythical, such as the Isle of Demons near Newfoundland, which might have come from local stories about a haunted island. The far-northern island of Thule was said to exist by a Greek explorer named Pytheas around 400 BC. However, details about where it was located were lost over time. Later, explorers and mapmakers guessed it might have been the Shetland Islands, Iceland, Scandinavia, or that it never existed at all. The island of Hy-Brasil was sometimes shown on maps west of Ireland, but all descriptions of it were imagined and not real.

Some phantom islands appeared because of mistakes in placing real islands or other errors on maps. Pepys Island was a wrong identification of the Falkland Islands. The Baja California Peninsula and the Banks Peninsula in New Zealand were sometimes shown as islands on early maps, but later it was found that they are connected to larger land areas. Isle Phelipeaux, which looked like a copy of Isle Royale in Lake Superior, appeared on maps for many years. It even helped mark the border between the United States and a region that later became Canada. However, later surveys showed that the island did not exist.

Sandy Island was shown on maps of the Coral Sea starting in the late 1800s. It was said to be between the Chesterfield Islands and Nereus Reef near New Caledonia. However, it was not found in the 1970s. Despite this, it remained on maps until 2012, when it was confirmed again that the island does not exist.

Other phantom islands were mistakes in identifying natural features such as waves, icebergs, fog, floating rocks from underwater volcanoes, or illusions. New South Greenland was seen in the Weddell Sea in 1823 but was never seen again. It may have been a mirage. Some islands, like Thompson Island or Bermeja, might have been real islands that were later destroyed by volcanic eruptions, earthquakes, landslides, or low areas like sandbanks that sank below sea level. Pactolus Bank, visited by Sir Francis Drake in 1578, might have been a sandbank that once existed.

In some cases, mapmakers intentionally added fake places to their maps, either to trick people or to test if others copied their work.