Yonaguni Monument

The Yonaguni Monument (与那国島の海底地形) is one of Japan’s most intriguing and controversial underwater destinations. Located just off the coast of Yonaguni Island, this submerged site consists of enormous stone formations with sharp edges, straight lines, and terraced surfaces that appear remarkably geometric. Their precise structure has sparked decades of debate among geologists and archaeologists alike—are they the result of natural tectonic forces, or the remnants of an ancient civilization lost beneath the sea? This enduring mystery draws divers from around the world, eager to witness the enigmatic formations firsthand.

Certified divers can join guided tours starting at around 12,000 yen, typically including transportation, tanks, and weights. For beginners, introductory or trial dives are available from approximately 20,000 yen. However, dives to the monument itself—often priced around 30,000 yen—are recommended only for experienced divers due to strong and unpredictable currents. Exploring the Yonaguni Monument is more than just a dive; it’s a journey into one of the ocean’s greatest unsolved mysteries—an unforgettable underwater adventure at the far edge of Japan.