There's this theory of a sunken land somewhere in the Pacific Ocean called Mu. Unlike the lost city of Atlantis, which has been mentioned in history by Plato, Mu's origin is more recent and is based on a theory of 19th century adventurer Augustus Le Plongeon, who said that major ancient civilizations of the world, like Egypt and those in Middle America, came from inhabitants of a continent called Mu. He originally placed this land in the Atlantic ocean, but later, James Churchwald insisted that it's submerged in the Pacific.
Well, years passed and this idea of Mu has somehow become legendary. Some proposed that island groups like the Philippines were once part of Mu. One archaeologist, has even found underwater structures in Yonaguni island in Japan that seemed carved out of rock. Professor Masaaki Kimura (top), marine geologist at the Department of Physics and Earth Sciences at the University of the Ryukyu, Okinawa, has studied the Yonaguni rock formations for years and is convinced that they were made by humans.
Kimura makes it clear that he does not believe the formations to be the remains of Mu, but it's his belief that the ruins may serve as a model for the legends and tales of sunken cities and continents. His critics say that since there are no definitive artifacts that point to human habitation, it's likely the angled rocks were formed naturally through tidal and other geological forces. As for Mu, well, scientific data simply does not support it's existence, thus it's largely regarded as simply the figment of an overactive imagination.