Frank Jacobs writes at Big Think:
A phantom island can be defined as ‘An island once believed to exist, and accordingly depicted on maps, but of which the existence was later disproved, and its cartographic representation removed’. These fallacies started infesting maps by the dozen during the Age of Discovery, when explorers sailing for regions unknown mistook their fevered ambitions, or a random fog bank, for islands that weren’t there.
Some of these phantom islands lingered on maps for centuries, at least partly, it seems, because they had such a great hold on the imagination of generation after generation of sailors. But eventually, they were proven not to exist. Gone from today’s maps are places with such captivating names as the Isle of Demons, Estotiland, the Island of the 11,000 Virgins, and Hy-Brasil. All of these and more were un-discovered, removed from nautical charts, and added to the select club of Phantom Islands.