Best time to visit Japan

Yonaguni Monument in Japan

The possibly humanmade underwater structure could date back to the ice age

Best time: November–June (all year round)

Yonaguni Monument
Yonaguni Monument
Yonaguni Monument
Yonaguni Monument

The Yonaguni Monument, also called Yonaguni Island Submarine Ruins, is an underwater rock formation south of the Japanese Ryukyu Islands, about 100 km east of Taiwan. Some scientists claim that the rock structures are stepped monoliths made by humans, and have existed for more than 10,000 years. It certainly looks more man-made rather than natural, but no official research or preservation efforts have been conducted on the site.

Discovered in 1986 by a diver, the site has also attracted scientists' attention. Masaaki Kimura, a marine geologist at the University of the Ryukyus, has been studying the object for many years and is convinced that the site was carved thousands of years ago when it was still above water. Precise angles and triangle carvings are unlikely to have a natural origin. He believes that the structure could be the remains of the Lost Continent of Mu, the Japanese Atlantis. However, other scientists don't agree and insist that geology and strong currents are responsible for the unusual shape of the rock.

Yonaguni Jima is an island near the southern tip of Japan's Ryukyu archipelago. Experienced divers can enjoy drift diving off the island year round. Even though the Monument is located close to the shore and it’s a shallow dive between 4.5 to 12 m (15 to 40 feet), sometimes the area is subject to strong currents, so divers have to be careful. From November to June you can spot schools of hammerhead sharks in the area.

Practical info

When is the best time to visit the Yonaguni Monument?

Diving around this area is possible throughout the year, but sea conditions are best from November-June. From July-October is typhoon season, and waters are rough and unpredictable. Visitors should exercise caution when diving as currents in the area can be strong. Experienced divers should take safety training before attempting to dive in this area. Show more

Where is Yonaguni Jima located and how do I get there?

Yonaguni Jima is situated at the southeast end of the Ryuku Islands. To get here, visitors can take ferries from the nearby islands or fly from major cities like Osaka or Tokyo to Yonaguni Airport. Dive sites are located on the western side of the island and visitors can travel here through a short drive from the port. Yonaguni Jima is also reachable by ferry from Taiwan. Show more

Is it safe to dive to the Yonaguni Monument?

Diving the Yonaguni Monument requires adequate training and experience since the currents can be unpredictable and strong. Divers are advised to use safety measures such as buoy markers, dive alerts, and avoid boat traffic. Inexperienced divers should avoid diving in this area, and those who still want to try are advised to look for a skilled guide. Show more

What other marine life can be spotted in the area besides the hammerhead sharks?

In addition to hammerhead sharks, the Yonaguni Monument offers an array of marine life, such as sea turtles, manta rays, tuna, and barracudas. The surrounding waters are home to over 300 coral species, making it an essential destination for those interested in marine life. Also, diving enthusiasts can witness the annual migration of humpback whales in the spring. Show more

What other unique activities or landmarks can be experienced on Yonaguni Jima?

Yonaguni Jima has some unique features aside from diving. A visit presents an opportunity to experience local customs, including their dialect and traditional festivals. For visitors who love horse riding, Yonaguni Horse Ranch offers horseback riding tours, while Yonaguni Healing Village is known for its hot spring. On-site also are tourist destinations such as the Yonaguni Castle Ruins and Yudomari Hot Spring. Show more

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Last updated: by Eleonora Provozin