Yonaguni is the westernmost inhabited island of Japan, part of the Yaeyama Islands in Okinawa Prefecture. It sits just over 100 kilometers from Taiwan and feels like the end of the map — remote, windswept, and filled with secrets. With a population of under 2,000, the island is known for its rugged cliffs, wild horses, and a deeply rooted culture that blends Ryukyuan, Japanese, and Pacific Islander traditions.

THE LOST CITY

What truly put Yonaguni on the map for divers and explorers alike was the discovery of massive underwater structures in the 1980s by a local diver. These formations, at depths of 5 to 30 meters, feature sharp angles, flat surfaces, and enormous stone “steps” that resemble a sunken city. Some geologists argue they are natural formations sculpted by tectonic activity and strong currents; others believe they are the remnants of a 10,000-year-old civilization lost to the sea.

THE LARGEST HAMMEHEAD GATHERING

In the remote waters off Yonaguni, Japan, divers can witness one of the largest hammerhead shark congregations in the world, set against a backdrop of some of the clearest ocean water on the planet. From January to March, hundreds of scalloped hammerheads gather in the deep blue currents that sweep past the island’s dramatic underwater cliffs and mysterious rock formations. The exceptional visibility—often exceeding 40 meters—creates a surreal experience, where the silhouettes of these majestic predators appear like ghostly sentinels drifting through liquid sapphire. This rare convergence of pelagic life and pristine conditions makes Yonaguni a true sanctuary for advanced divers seeking an unforgettable encounter.