- Where
- Izu Islands
Tokyo Metropolis, Japan - Coordinates
- 32.4570° N
139.7670° E - Biome
- Subtropical volcanic island
- Area
- 8.75 km², pop. c. 170
- Status
- Class C active volcano
- Best visited
- April–June, Sept–Nov
The short answer
Aogashima is a volcanic island in the Izu chain, about 350 kilometres south of Tokyo and administered by it, covering 8.75 square kilometres. Around 170 people live there, making it the least populated village in Japan. The island is a double caldera: a large outer crater called Ikenosawa with a secondary cone, Maruyama, rising from its floor, and the village sits inside. It is classified by the Japan Meteorological Agency as a Class C active volcano, the lowest of three alert tiers.
Why it's worth knowing
The shape is the thing. Sheer cliffs rise straight out of the Pacific on every side, then drop away inwards into a green bowl, and inside that bowl is another, smaller volcano. People live in the gap between them. Seen from the air it looks less like geography than like a diagram of itself.
The second thing is that this is Tokyo. Administratively, legally, postally: Tokyo. The same metropolis that contains Shibuya Crossing also contains a village of 170 people on the rim of an active crater, reachable only when the sea permits.
The field notes
1785
The island's current shape dates from a catastrophic eruption in 1785, following several years of increasing seismic activity. It destroyed nearly all vegetation and killed a large proportion of the roughly 327 people then living there. The survivors evacuated to Hachijōjima, and Aogashima stood empty for around fifty years before people returned.
They returned because the island, for all its obvious hostility, offers a rare combination: volcanic soil that grows crops, fresh water from natural springs, fish in the surrounding Kuroshio Current, and free geothermal heat. That last item is not incidental.
Hingya
Steam vents constantly from fissures between the inner and outer craters. The islanders call it hingya, and they have built the practical life of the village around it. There is a communal steam cooker where you can put in eggs or sweet potatoes and come back later. There is a public geothermal sauna and bathhouse. And there is a salt works: seawater from the Kuroshio Current evaporated using nothing but volcanic steam, producing Hingya salt, which is sweeter than ordinary salt because the current's water carries markedly more calcium.
It is a closed loop of a kind almost nowhere manages — the hazard and the utility are the same object.
Getting on and off
Access is the defining fact of life here. There is no airport. One ferry a day runs from Hachijōjima, and by widely repeated local accounting it is cancelled roughly 60 per cent of the time, sometimes for a week at a stretch, because of wind and swell at the tiny harbour. A helicopter runs once daily with around nine seats, cancelled perhaps 30 per cent of the time.
The practical strategy is to base yourself on Hachijōjima near the port and go when conditions allow — and to accept that you may also be stuck on Aogashima for several days longer than planned. Some visitors consider that the good outcome.
An egg cooked in the ground. At the hingya vents there is a communal steam cooker: a lidded box over a fissure where the island's own heat comes up. You lower in eggs or sweet potatoes, wait, and eat something warmed by the volcano you are standing inside. It costs nothing and it has never once been switched off.
Getting there
Everything routes through Hachijōjima, 70 kilometres north, which has an airport served from Tokyo and an overnight ferry. From there, the Aogashima ferry takes about two and a half hours; the helicopter takes twenty minutes and needs booking well in advance.
Accommodation is a handful of small minshuku guesthouses and a free island campsite — all of which must be reserved before arrival. There is one general store. A rental car is close to essential, since the single road climbs from the port over the crater rim to the village. The Oyama Observation Park viewpoint gives the classic view down into the double caldera, and the absence of light pollution makes the night sky extraordinary.
Common questions
Where is Aogashima?
Aogashima is a volcanic island in the Izu chain, roughly 350 kilometres south of Tokyo in the Philippine Sea, and is administered as part of Tokyo Metropolis. It covers 8.75 square kilometres and is the southernmost and most isolated inhabited island of the Izu group.
How many people live on Aogashima?
Around 170 people live on Aogashima, which makes it the least populated village of any municipality in Japan. Accommodation for visitors is limited to a few small guesthouses and a single island campsite, all of which must be booked in advance.
Is Aogashima an active volcano?
Yes. Aogashima is classified by the Japan Meteorological Agency as a Class C active volcano, the lowest of three alert levels. Its last major eruption was in 1785; geothermal steam still vents continuously from fissures between the inner and outer craters.
What happened on Aogashima in 1785?
A catastrophic eruption in 1785 destroyed nearly all vegetation on Aogashima and killed a large proportion of the roughly 327 residents. Survivors evacuated to Hachijojima, and the island remained uninhabited for around fifty years before people returned.
What is hingya?
Hingya is the local name for the geothermal steam that vents from fissures on Aogashima. It is odourless and non-toxic, and islanders use it to run a communal steam cooker, a public sauna and bathhouse, and a salt works that evaporates Kuroshio Current seawater using volcanic steam alone.
How do you get to Aogashima?
Aogashima is reached only via Hachijojima, 70 kilometres north, by a daily ferry taking about two and a half hours or a helicopter taking twenty minutes with around nine seats. The ferry is reportedly cancelled roughly 60 per cent of the time due to wind and swell, so visitors are advised to base themselves near the Hachijojima port and travel when conditions allow.
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