A phantom island is a place that was once thought to be an island and was shown on maps, but later discovered to not exist. These islands often came from the reports of sailors who explored new areas, and were usually caused by mistakes in navigation, incorrect observations, unconfirmed stories, or made-up information. Some phantom islands stayed on maps for many years before being proven not to exist.

Unlike lost lands, which people say once existed but were destroyed by the sea or other events, a phantom island is a place that was claimed to exist at the same time as the people who reported it, but was later found not to exist at all. For example, some phantom islands were found not to be islands, like the Island of California.

Examples

Some islands may have been completely mythical, like 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 the 4th-century BC Greek explorer Pytheas, but details about where it was located were lost. 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.

Some phantom islands appeared because of mistakes in maps, such as placing real islands in the wrong spot or other errors. Pepys Island was a mistake that confused 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 their mainlands. Isle Phelipeaux, a copy of Isle Royale in Lake Superior, was shown on maps for many years and even used as a landmark for the border between the United States and what would become Canada. However, later surveys showed it did not exist.

Sandy Island appeared 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. Even so, it remained on maps until the early 2000s, when it was confirmed again not to exist in 2012.

Other phantom islands were mistakes in identifying natural features, such as waves, icebergs, fog, floating rocks from underwater volcanoes, or illusions. New South Greenland, seen in the Weddell Sea in 1823 but never found again, might have been a mirage. Some islands, like Thompson Island or Bermeja, might have been real islands destroyed by volcanic eruptions, earthquakes, underwater landslides, or low areas like sandbanks that sank below water. Pactolus Bank, visited by Sir Francis Drake in 1578, might have been a sandbank that no longer exists.

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