Yonagunijima: Japan's Westernmost Border Island Overlooking Taiwan

Yonagunijima, in Okinawa Prefecture, is an inhabited island located at the westernmost point of Japan. A "border island" only about 111 kilometers from Taiwan, on clear days with clear air you can even gaze at the mountain shadows of Taiwan beyond the sea. Also known as the island where the sun sets last in Japan, it is a secluded land where majestic nature and a distinctive culture remain strongly. With a coastline of rugged cliffs continuing on, mysterious underwater ruins, and pastoral scenery where the native Japanese Yonaguni horses leisurely graze, it is an island brimming with charms completely different from the mainland.

"Irizaki," Japan's Westernmost Superb Scenery

"Irizaki," located at the western tip of Yonagunijima, is the westernmost point of Japan. At the cape stand a monument indicating Japan's westernmost point and a lighthouse, and you can take in the endlessly spreading East China Sea at a glance. This is also famous as the place where the sun sets latest in Japan, and the superb scenery of the sun setting on the horizon is exceptional. If conditions are right, you can also gaze at the island shadow of Taiwan far in the distance. It is a spot you cannot miss if you visit Yonagunijima, where you can savor the special sense of accomplishment of "having stood at the western end of Japan."

Mysterious Underwater Ruins and Diving

The waters around Yonagunijima are known as a place divers long for. Among them, the "underwater ruins" seen on the seabed south of the island are a giant staircase-like rock structure that also looks man-made, and debate continues over whether their formation is man-made or natural, drawing the interest of many divers and researchers. It is also known as a diving spot where, in winter, you can encounter schools of large hammerhead sharks that migrate in, letting you experience a powerful underwater world in the highly transparent sea.

Access and Basic Information

For Yonagunijima, using an airplane from Ishigakijima or from Naha Airport on Okinawa's main island is common, and a ferry also operates from Ishigakijima (services are few, so check the timetable in advance). It is a remote island located about 127 kilometers west of Ishigakijima and roughly 500 kilometers southwest of Naha. Travel on the island centers on rental cars, rental motorbikes, and rental bicycles, and public transport is limited. It has a subtropical climate and is mild year-round, but spring to early summer is when the sea is calm and comfortable. Diving aimed at hammerhead sharks is in season in winter.

Practical Travel Notes

• Planning how to get there: Yonagunijima has limited services for both flights and ferries. Because they can be canceled due to weather, allowing a spare day in your itinerary is reassuring. Book lodging and rental cars early as well.
• Travel on the island: Route bus services are few and the highlights are scattered across the island, so a rental car or rental motorbike is convenient. When driving, also watch for Yonaguni horses darting out.
• Diving: Diving at the underwater ruins and for hammerhead sharks has participation conditions depending on experience and sea conditions. Consult and reserve with a shop in advance. In winter there are also days when the sea is rough.
• Items and shopping: Because it is a remote island, shops and facilities are limited. It is reassuring to prepare necessary daily items, cash, and sun protection in advance.

A Word of Advice

Yonagunijima is a remote island located at the westernmost point of Japan, and flights and ferries are sometimes canceled due to weather. Make plans with room to spare for travel and activities, and check the latest operation status. The underwater ruins are a mysterious spot whose formation remains unexplained and debated, and the winter hammerhead sharks are a diving highlight known worldwide. Try savoring the majestic nature and distinctive culture unique to Japan's western edge slowly, with time to spare.

📚 Sources

This article draws on tourism guidance from Yonaguni Town, published information on the westernmost point Irizaki and the undersea formation, guidance from diving operators on Yonaguni, and flight information from the airlines serving Yonaguni Airport and ferry information from Ishigaki. Descriptions of the hammerhead sharks and Yonaguni horses follow local and operator guidance. Flight and ferry frequency and operating status change with the weather, so please confirm details on each operator official sources before visiting.

Visitor Checklist

• Trip planning: Both flights and ferries to Yonaguni are limited and may be cancelled due to weather, so keep a backup day and book lodging and rental cars early.
• Getting around: Local buses are few and sights are spread out, so a rental car or scooter is handy; watch for Yonaguni horses entering the road when driving.
• Diving: Diving at the undersea formation or with hammerhead sharks has conditions based on experience and sea state, so consult and book with a shop in advance; the sea can be rough in winter.
• Supplies and shopping: As a remote island, shops and facilities are limited, so prepare daily necessities, cash, and sun protection in advance.
• Best season: The calm, comfortable season is spring to early summer; diving for hammerhead sharks is a winter activity.