Yonaguni Monument: A Natural Formation or Submerged Ruins?

Yonaguni Monument: A Natural Formation or Submerged Ruins?

By Theodora “Theo” Marsh · Published May 8, 2026 · Updated May 13, 2026 Last reviewed: May 8, 2026. Direct Answer: What Is the Yonaguni Monument, and Is It Built or Born? The Yonaguni Monument is a submerged sandstone formation off the southern coast of Yonaguni-jima in Japan’s Ryukyu chain, discovered by sport diver Kihachiro […]