Roughly 25m underneath the waters of Japan lies an underwater rock pyramid. No one knows who constructed it and when; however, it exists, accessible to anyone who wishes to go down and investigate. It is known as Yonaguni Monument.
The Japanese archipelago extends for almost 4,000 Km-from Kamchatka Peninsula to the island of Taiwan in China.
The Yonaguni island is situated at southwestern’s furthest tip which Japan’s most western point, and only 100Km away from Taiwan.