The Shimanami Kaido: Cycling Between Islands from Onomichi

The Shimanami Kaido is a road across the Seto Inland Sea from Onomichi in Hiroshima Prefecture to Imabari on Shikoku, hopping six islands over seven bridges. Alongside the traffic lanes runs a dedicated cycleway the whole distance.

That is what makes it unusual. This is not a road you share with lorries — the bridges carry separated bike lanes, reached by long spiral ramps, and the island sections follow a blue line painted on the road surface that navigates the entire route for you. You genuinely do not need a map.

It is widely rated one of the best cycle routes in Asia, and the reason is that combination: real infrastructure, sea on both sides for most of the day, and almost no navigation stress.

Less hard than the distance suggests. There is no serious climbing — the only gradients are the bridge approach ramps, which are engineered at a gentle grade precisely so that bicycles can manage them. The island roads between are flat to rolling.

Seventy kilometres is still seventy kilometres. A regular cyclist does it in six to eight hours with stops; an unfit rider on a rental will find the last twenty a grind. The comfortable version is two days with a night on Omishima or Ikuchijima, which also lets you actually stop at things.

The genuinely useful escape hatch is that you can shorten it at will. Ferries connect several islands back to the mainland, and the standard half-route — Onomichi to Omishima, roughly 40 km — captures most of the best bridges. Ride until you have had enough and take a ferry.

Rental terminals sit at both ends and at several points along the route, and the system is built for one-way riding: pick a bike up in Onomichi, ride to Imabari, hand it in there. You do not have to come back.

That single detail is what makes the route practical for travellers rather than only for cyclists with their own gear. Standard cross bikes, e-bikes and road bikes are all available; e-bikes are the sensible choice for anyone unsure about the distance, and they book out first in season.

Bridges carry a small toll for cyclists at some crossings. Reserve bikes ahead on weekends and through spring and autumn — this route is well known domestically and the terminals do run out.

Spring and autumn are the seasons. Summer on the Inland Sea is hot and humid with little shade on the bridges; winter is rideable but the sea wind on the spans is cold and exposed.

Worth stopping for: Ikuchijima's Kosanji Temple and its startling white marble hilltop; the Museum of Art on Omishima; citrus groves — this coast grows a lot of Japan's lemons; and the small ports where the ferries call, which are ordinary working places rather than sights.

Onomichi itself deserves an evening. It is a hillside town of temples and cats reached by narrow stairways, with a well-known ramen style of its own, and it is a far better place to start or finish than a station platform. Most people rush it and regret it.