A pillar, a monkey and a goblin: the rocks around Okinoshima have the kind of names that sailors give to things that frightened them. Mikadobashira is one of a small cluster of sea stacks that rise out of the water close to the sacred island, along with Kozaru-jima and Tengu-iwa, and they count as part of the World Heritage listing. Together they work as a natural boundary to the holy ground, jagged rock where the swell breaks white even on calm days.
The sea here is the Genkai Sea, a part of the Tsushima Strait, the narrow and dangerous passage between Kyushu and Korea. For centuries ships crossed it on their way to Silla and Tang China, and Okinoshima was their landmark, the last piece of Japan and the first. Those rock pillars would have been visible long before the island itself, and a wrecked ship here was a common story. Offerings made on the island were meant to buy safe passage. In 1905, the Japanese fleet fought and destroyed the Russian Baltic fleet in these same waters, an event so loud that people on Okinoshima reportedly heard the guns.
You cannot land at these rocks, and you cannot ride to them. For a rider the practical business is on the Munakata coast of northern Kyushu, where there are good coastal roads, small harbours and a calm, unhurried fishing country. Fukuoka is the big city nearby, with all the fuel, food and repair shops you could want. From the shoreline at Oshima, reached by ferry, and in clear weather, you might catch the pale line of the island and perhaps its outlying rocks on the horizon.
Respect is the order of the day. Fishermen and shrine priests have kept to the rules here for generations, and the idea of a place that can be seen but not touched is one of the strongest things about it.
If you plan to look, go on a clear winter or autumn morning, when the air is sharp and the visibility long. Summer haze and typhoon swell hide the sea beyond the nearest few miles.