The structure is located near Yonaguni Island in Japan,  just five meters below the water’s surface. It is reminiscent of a pyramid, with structures that look like castle ruins, temples, arches, and a stadium, all seemingly connected by roads.

A local first discovered the structure in 1986, when diving in the area.

Some believe the site to be the remnants of an ancient civilization, possibly dating back 10,000 years, which might have been sunk by a tsunami, a common occurrence in Japan for centuries.

Japanese marine geologist Masaaki Kimura, who has studied the Yonaguni Monument for years, argues that “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.”

Specifically, he estimated that the timeline aligns with the Jomon era, whose inhabited the Japanese archipelago around 12,000 BCE.

However, others are not so quick to draw conclusions of a “Japanese Atlantis”.

Boston University professor Robert Schoch believes that the structure is all natural, commenting in the National Geographic that “It’s basic geology and classic stratigraphy for sandstones, which tend to break along planes and give you these very straight edges, particularly in an area with lots of faults and tectonic activity.”

However, Kimura insists that “it’s very difficult to explain away their origin as being purely natural, because of the vast amount of evidence of man’s influence on the structures.”

No definitive conclusions have been drawn.

And so the mystery continues…