After years of searching, and combing the Pacific for a possible lost land that could have been the root of one of these legends, it is clear that there is no extra continent in the sea. However, in 1986, a SCUBA diver, Kihachiro Aratake, diving off the coast of the island of Yonaguni-jima discovered something that may lend credence to the existence of Mu or Lemuria. On the sea floor he found vast geometric structures cut out of the rock. There was evidence of stairs, and improbable angles in the stone. He marked the location for future divers, and in the intervening years these undersea ruins have come to be known as the "Yonaguni Monuments".
Efforts to date the monument are derived from the last time the area was above sea level, which would have been approximately 8,000-10,000 years ago-- about 3-5 millennia before Egypt's pyramids were erected. If the monuments were indeed built by humankind, it would require some dramatic revisions to the accepted chronological history of humanity.
But as clearly defined as the structures are to some, there are others who disparage the tale of the Yonaguni Monuments. No chambers or entrances have ever been found into the monuments, and no tools have been found in the vicinity to clearly indicate human involvement. Many assert that the formations can be attributed to erosion or coral settlements. The sharp angles and lines in the stone may be the result of the way the stones erode-- breaking off at right angles. One can look to the cliffs above the sea to observe that the regional stone tends to erode in a way that leaves naturally sharp angles.
Because of the submerged location and the strong currents in the area, the Yonaguni Monuments have proved difficult to properly study; though the area has become a popular site for SCUBA tours. Researchers have not yet found conclusive evidence implicating either erosion or humanity as the source of these shapes, so the investigation and debate regarding the nature of the Yonaguni Monuments continues.