Yonaguni Monument

The sandstone structure stretches 165 feet in length and 65 feet in width, featuring multiple terraces and geometric shapes beneath the ocean surface.

Marine geologist Kihachiro Aratake discovered the formation in 1986 while searching for hammerhead sharks in the waters of the Ryukyu Islands.

The formation generates discussions between researchers who interpret it as an ancient stepped pyramid and geologists who classify it as natural sandstone weathering.

Scuba divers can access the monument at depths of 85 feet, where water temperatures range from 68 to 82 degrees Fahrenheit throughout the year.

The monument contains straight edges, sharp corners, and parallel faces that form distinct geometric patterns in the underwater landscape.

Location: Yonaguni

GPS coordinates: 24.43604,123.01147

Latest update: May 26, 2025 19:11