Oshima island is a nice getaway from Tokyo. Located between Izu and Boso, it can be reached in less than two hours via jetfoil from Takeshiba Ferry Terminal. The island has a coastline of 52 km and a maximum elevation of 764 mt. It is possible to cycle around the island on a day trip, but the pace of riding will have to be fast as the last ferry departs early in the afternoon. I recommend spending a night there.

Day 1

Moving time: 2:46:54 – Distance: 39.8km – Climbing: 951m

I visited Oshima in April 2019 with a friend who was traveling in Japan from Europe. During the first day of the trip, we followed the east coast from north to south. Starting in Okata, we climbed Mount Mihara and headed to Habu city. The weather, as you can see from the photos below, was unforgiving.

In a thick fog, the volcanic landscape was eerily beautiful. Unfortunately, the fog meant that we could not appreciate the view from the top of Mt. Mihara. I suggest you to search on the Internet for panoramic pictures of Mt. Mihara. You will see what we missed.

The climb to Mt. Mihara, around 600mt of elevation, was made easy by gentle gradients and well-paved roads. On the top of the volcano, there is a hotel with an onsen and convenience store. From there, several trekking trails extend to the summit of the mountain and toward Mihara’s black desert.

Mt. Mihara is an active volcano with major eruptions occurring in cycles of 100–150 years. Back in 1923, Oshima island marked the epicenter of the Great Kantō earthquake, which brought havoc on Tokyo and caused more than hundred-thousand deaths. The last big eruption of Mt. Mihara happened in 1986 when all inhabitants of Oshima were safely evacuated. There are emergency shelters scattered all over the island, and it’s always good to keep note of where the closest one is. 

After descending Mt. Mihara, we headed to Habu city. The east coast is mostly inhabited and void of traffic. Tourist spots include the Ura-Sabaku desert and the Fudeshima Rock. In Habu city we stayed in a wonderful traditional guesthouse along the coast. The owner was very kind to arrange our dinner. She also gave us some home-made riceballs for breakfast. 

Day 2

Moving time: 1:06:39 – Distance: 21.8km – Climbing: 336m

On the second day of our trip, we rode north to Okata to catch a ferry to Atami. The west side of the island is more densely populated and less rugged. The road was still very pleasant, with many short climbs and descents along the way. The most scenic spot on the route is the Semba Volcanic Cliff — a 700mt long cliff that exposes volcanic sediments accumulated over the 15,000 years lifetime of the island. 

On the northern tip of Oshima there are more tourist attractions that we, unfortunately, had no the time to visit. Altogether, Oshima is a beautiful island rich in history and unique landscapes. Only a few hours away from Tokyo, it makes for the perfect getaway. Cyclists will particularly enjoy the quiet coastal roads and Mt. Mihara’s climb.

Useful links:
Oshima Navi: https://oshima-navi.com/index.html
Ferry to Oshima: https://www.tokaikisen.co.jp/newship2020/