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 go 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. Unfortunately, the weather was not the best. It was cold, foggy, and rainy. 

The volcanic landscape was eerily beautiful with the dense fog. However, I do wish we had been met by the sun. The view from Mt. Mihara is stunning on a sunny day. On the top of the mountain it is possible to see the whole Izu peninsula and Sagami bay on the backdrop of Mount Fuji. Since all my panoramic photos consists of white fog, I invite you to search on the Internet for pictures of Oshima and Mt. Mihara.

The climb to Mt. Mihara, around 600mt of elevation, is 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. All over the island there are emergency shelters, and it’s always good to keep note of where is the closest one. 

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 that have accumulated over the 15,000 years lifetime of the island. 

On the northern tip of Oshima there are more tourist attractions that we, unfortunately, hadn’t the time to see. 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 particularly will 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/