The Yonaguni monument as a claimed sunken civilization

Record summary

The underwater terraces and ledges near Yonaguni Island have been promoted by some writers, including Graham Hancock, as the remains of a prehistoric city or pyramid submerged after catastrophic sea-level change. Marine geologist Masaaki Kimura has argued for human modification, whereas other geologists identify natural sandstone jointing, fractures, and erosion as sufficient explanations. The structures are outside the Middle East and North Africa, but they are a useful comparative case for evaluating recurring claims about postglacial inundation and lost civilizations. No scholarly consensus establishes a built city.