Some 960 km off the coast of Africa, a huge grid appeared to mark the seafloor on Google Earth images. There was some immediate buzz about the fabled (almost certainly mythical, but still fascinating) lost city of Atlantis.
Alas, Google explained it was not so. The apparent grid was an artifact of the way we've been studying the seafloor. Contour data taken directly from sonar mapping systems is shown in relatively straight lines - the tracks of the ships that carried the sonar and did the mapping. The spaces between are unmapped areas.
COMMENT: Too bad about Atlantis (which probably arose from a mangled account of the Minoan civilization), but think about it the other way. Think about how much unknown seafloor territory is indicated by these images and how much exploration we have left to do. As Sylvia Earle once put it, we know more about Mars than the deep oceans.