They usually originate from the reports of early sailors exploring new regions, and are commonly the result of navigational errors, mistaken observations, unverified misinformation, or deliberate fabrication.
Some may have been purely mythical, such as the Isle of Demons near Newfoundland, which may have been based on local legends of a haunted island.
Nonetheless, it continued to be included in mapping data sets into the early 21st century, until its non-existence was re-confirmed in 2012.
[2][3][4] Other phantom islands are misidentifications of breakers, icebergs, fog banks, pumice rafts from underwater volcanoes, or optical illusions.
In some cases, cartographers intentionally include invented geographic features in their maps, either for fraudulent purposes or to catch plagiarists.