Suō-Ōshima

Yashiro Island, commonly referred to as Suō-Ōshima, is a large island in eastern Yamaguchi Prefecture connected to the mainland by the Ōshima Bridge near Yanai. The island is one of the better road cycling destinations in western Japan thanks to its mild climate, relatively low traffic volumes, and extensive network of coastal roads.

While “Suō-Ōshima” is the name most commonly used in tourism materials and road signage, the island’s proper geographic name is Yashiro Island.

The Route

Yashiro Island is not flat, but the terrain is generally rolling rather than mountainous along the coast. Most climbs are short and irregular, with frequent descents back to sea level. Riders attempting a full island loop should still expect a meaningful amount of accumulated elevation gain.

The western side of the island tends to have the steepest and narrowest roads. Some sections feature short climbs above fishing villages with gradients exceeding 10%, though these are rarely sustained for long distances.

Road surfaces are mostly good throughout the island. However, some of the quieter coastal sections can have debris, sand, or vegetation on the shoulder, particularly after storms.

Getting there and away

Honshu

Oshima Bridge connects Suo-Oshima to the mainland right at Obatake Station in Yanai which gives train access to Yamaguchi and Iwakuni. Take the train to Tokuyama for the nearest Shinkansen (Sanyo).

Ferry to Matsuyama

The Boyo Ferry offers about 10 services a day from Yanai to Matusyama make an entryway to Shikoku. Of those 3 of the ferries make a stop at the east end of the island in Ihota (伊保田) before heading on to Matsuyama. (See schedule in Japanese here, has auto translate funciton to English)