Expedition Unknown (2015)

S2E7 Japan's Atlantis

Gates travels to the Yonaguni Island ruins, located in the East China Sea, to investigate whether the underwater formations are natural or crafted by humans. Kihachiro Aratake, who first uncovered the Yonaguni Monument, joins Josh for a dive, revealing the submerged site featuring cut steps that ascend to a flat platform. Josh collects a rock sample for further geological testing. Meanwhile, in Osaka, archaeologist Michio Maezano presents Josh with an ancient rock tomb, suggesting that early civilizations might have created the Yonaguni structures, which could have been submerged by an earthquake.