A South Pacific island, shown on marine charts and world maps as well as on Google Earth, does not exist, Australian scientists say.
The supposedly sizeable strip of land, named Sandy Island on Google maps, was positioned midway between Australia and French-governed New Caledonia.
But when scientists from the University of Sydney went to the area, they found only the blue ocean of the Coral Sea.
More at the link.
I recall Alex posting about maps where fake towns were added so that the copyright holder could ensnare those who copied their maps, could this stem from the same reason?