Oshima Travel Guide

Oshima (大島), formally Izu Oshima, is the largest of the Izu Islands and sits roughly 100 km south of central Tokyo, yet administratively belongs to Tokyo Metropolis. Despite that urban affiliation, the island feels worlds apart — a rugged, largely forested volcanic island dominated by the still-active Mount Mihara (三原山), which last erupted in 1986.

The island's terrain ranges from black lava fields and ash plains near the caldera to verdant camellia groves along its gentler slopes. Its coastline is dotted with black sand beaches, sea cliffs, and small fishing harbors. The main settlement, Motomachi, sits on the island's northwestern side and is where most services, accommodation, and ferry facilities are concentrated. A smaller port, Okada, on the northern tip, also handles ferry traffic.

Oshima draws visitors seeking a genuine break from Tokyo's density — hikers, nature photographers, cyclists, and those simply wanting a slower pace. It is not a resort island in the developed sense; infrastructure is modest and that is, for many travelers, precisely the appeal.

Visas

Oshima is Japanese territory and subject to Japan's standard entry requirements. For visa guidance, check TravelerPulse's Visas section and the Japanese Ministry of Foreign Affairs website for the rules applicable to your nationality.

What to Pack

• Sturdy hiking footwear is strongly recommended; lava-field trails can be uneven.
• Layers are essential. Sea winds shift quickly and summit temperatures are noticeably cooler than sea level.
• Rain gear year-round — the island receives substantial rainfall, particularly during the June–July rainy season and typhoon months (August–September).
• Cash. While urban convenience stores accept cards, many smaller restaurants and guesthouses are cash-preferred. ATMs at Japan Post locations on the island are generally the most reliable for foreign cards; verify availability locally.

Typhoon Season

August and September bring heightened typhoon risk. Ferry services can be suspended or delayed at short notice, sometimes for multiple days. Build flexibility into travel plans during this period.

By Ferry

The primary way to reach Oshima is by ferry from Tokyo (Takeshiba Pier) or from ports in Atami or Ito on the Izu Peninsula. Tokai Kisen is the main operator serving Oshima. Services range from overnight large ferries to faster high-speed jet foil services that reduce crossing time significantly. Schedules and routes vary by season; check current timetables directly with Tokai Kisen or verify locally, as sailings change and weather-related cancellations are common.

By Air

New Central Airservice operates small aircraft between Tokyo's Chofu Airport and Oshima Airport. Flight time is short, though the route operates with small propeller aircraft and is subject to weather cancellations. Verify current schedules and seat availability directly with the airline, as service frequency varies seasonally.

Arriving on the Island

Ferries dock at either Motomachi Port or Okada Port depending on sea and wind conditions. The port of call may be decided the night before or morning of arrival, so remain flexible and check with the ferry operator. Buses connecting the two ports and key island areas operate in coordination with ferry arrivals; confirm current routes locally.

Oshima is roughly 91 km² and the main road encircles the island. Getting around independently is the most practical approach.

Options

• Rental car or scooter: Available near the ferry terminals; this is the most flexible option for covering the island at your own pace. Book in advance during peak seasons.
• Rental bicycle: Suitable for the coastal perimeter road in good weather, though the road has notable elevation changes near Mihara. Electric-assist bikes are available and worth considering.
• Bus: A public bus network connects major points including Motomachi, Okada, and the Mihara summit area (seasonal). Schedules are infrequent; verify current routes and times locally.
• Taxi: Available but limited in number. Confirm availability for early morning or late evening trips.

Walking is realistic within Motomachi itself but distances between key sites make some form of transport necessary for most itineraries.

Accommodation on Oshima is dominated by minshuku (family-run guesthouses) and a small number of hotels and pension-style lodgings. Most are clustered in or near Motomachi, with some options near other parts of the island.

Minshuku stays often include meals (dinner and breakfast), which is convenient given the limited restaurant options and is frequently good value. Confirm meal inclusion when booking. Some guesthouses have staff with limited English; a translation app is a useful tool.

There is a campsite in Oshima Park; verify current operating status and reservation requirements locally before planning to camp. Peak seasons — March–May and July–August — warrant advance booking. Outside these periods the island sees modest visitor numbers and accommodation is generally easier to secure.

Verify current listings and book through major Japanese accommodation platforms or directly; TravelerPulse recommends confirming details — including payment methods — directly with the property.

Mount Mihara (三原山)

The volcanic caldera is the island's defining attraction. Trails lead from a visitor center area to the outer rim and, on clearly marked paths, closer to the inner crater. The landscape of hardened black lava, volcanic ash, and sparse vegetation is unlike anything on the mainland. Check current volcanic activity advisories before hiking; the Japan Meteorological Agency monitors and publishes alert levels.

Oshima Park and Camellia Forest

Oshima is sometimes called the "Camellia Island" — it claims a very large number of wild camellia trees. Oshima Park in the north of the island contains a botanical garden area focused on camellia varieties and is typically at its best from late January through late March. Entry fees and hours — verify locally.

Ura-Sabaku (Desert of Oshima)

A broad expanse of volcanic ash and sand on the island's eastern flank, locally nicknamed a desert. It is striking in its barrenness and offers an unusual landscape walk. The area featured in the 1986 eruption documentation and the ash layers are visible in the terrain.

Coastline and Beaches

The island's beaches are composed of dark volcanic sand. Habu Port area on the southeastern coast offers a quiet, scenic anchorage. Swimming is possible at designated beaches in summer; observe local safety advisories and flag systems.

Cycling the Perimeter

The roughly 50 km perimeter road is a popular cycling route, taking in ocean views, fishing villages, and dramatic sea cliffs. Allow a full day and check weather forecasts carefully.

Oshima's food scene is small, local, and tied closely to what the sea and the island produce. Do not expect a wide range of restaurant options, particularly outside Motomachi.

What to Eat

• Kusaya: A pungent dried fish fermented in a brine unique to the Izu Islands. It is an acquired taste and considered a regional specialty. Visitors are often surprised by the strong aroma.
• Fresh seafood: Sashimi and grilled fish using locally caught varieties are available at restaurants and guesthouses. Quality is generally high.
• Akasatsu: A locally produced salt harvested from the surrounding sea, used in island cooking.
• Island vegetables and pasture products: Some guesthouses (minshuku) serve set meals featuring locally sourced produce; this is often the best way to eat well on a budget.

Where to Eat

Most restaurants are concentrated in Motomachi. Hours can be limited and some places close on short notice; it is worth asking your accommodation for current recommendations. Convenience stores (open later hours) near the port serve as reliable fallback options for snacks and basics.

Money

Carry sufficient yen cash. Post office ATMs are the most reliably accessible for international cards; hours vary, so check upon arrival.

Mobile and Internet

Major Japanese mobile networks (docomo, au, SoftBank) cover most of the island, though coverage may weaken in the caldera interior or dense forest areas. Wi-Fi is available at some accommodations; confirm in advance.

Postal and Medical

There is a post office in Motomachi. Medical facilities on the island are limited; a clinic serves basic needs, but serious medical situations may require evacuation to the mainland. Travel insurance that includes medical evacuation is advisable.

Language

English signage exists at major tourist sites and the ferry terminals, but is limited elsewhere. A translation app and basic Japanese phrases will be genuinely useful.

Emergency Numbers

• Police: 110
• Fire and Ambulance: 119

These are Japan-wide standard numbers.

Oshima is a safe destination by most measures. General personal safety concerns are low, consistent with rural Japan broadly.

The principal safety considerations are environmental:

• Volcanic activity: Mount Mihara is active. Monitor the Japan Meteorological Agency's volcanic alert level before and during hiking. Follow all posted signs and do not enter restricted zones.
• Typhoons and rough seas: Storms can strand travelers for multiple days if ferry services are suspended. Maintain flexibility in your schedule August through October.
• Ocean swimming: Currents around volcanic island coastlines can be unpredictable. Swim only at designated beaches and observe any flag or sign systems in place.
• Trail conditions: Lava field trails can be slippery when wet. Stay on marked paths.