In 1986, a diver off Yonaguni Island found huge underwater rock terraces with flat surfaces and sharp right angles. Marine geologist Masaaki Kimura argues they were shaped by people. Most geologists think the rock simply split that way.
Truth label: Debated. Serious people disagree. You get both sides.
Go deeper
The case for
Kimura points to what he sees as steps, a road and carved shapes.
The case against
Sandstone here naturally fractures along straight lines, and similar shapes appear on land nearby.
Learn
- If it were built. It would have been above water at the end of the Ice Age, over 10,000 years ago.
Test yourself
What kind of rock forms the Yonaguni monument?
Sandstone. It is mostly sandstone and mudstone, which splits in straight lines.
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