These 10,000 Year-Old Sunken Ancient Ruins in Japan Remain a Huge Mystery

There's a mysterious 10,000-year-old massive underwater monument off the coast of Japan. 

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Source: Wikimedia Commons

It's called the Yonaguni Monument, located off the coast of Yonaguni, the southernmost of the Ryukyu Islands, and scholars have yet to figure out whether it's man-made or natural. 

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Source: Wikimedia Commons

But an expert told National Geographic the structures found in the monument by divers suggest it was man-made in Asian culture. 

"The characters and animal monuments in the water, which I have been able to partially recover in my laboratory, suggest the culture comes from the Asian continent," he said.

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Source: Wikimedia Commons

Experts have discovered 10 distinct structures in the area that could be ruins of an ancient city. 

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Source: Wikimedia Commons

Decades of research by scuba divers shows the sunken city likely submerged at once during a massive earthquake of sorts.

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Source: Pinterest

Divers have found evidence of ruins of a castle, triumphal arch, five temples and a stadium.

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Source: Wikimedia Commons

They call it the "Japanese Atlantis."

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Dr. Robert M. Schoch, a Boston University professor who's conducted field research at ancient sites in Egypt as well, believes it could be a natural formation. "We should also consider the possibility that the Yonaguni Monument is fundamentally a natural structure that was used, enhanced, and modified by humans in ancient times," he wrote in his book Voices of the Rocks.