Aogashima

Seen from the air, Aogashima looks like a volcano that has swallowed a smaller volcano. The outer island is a steep-walled ring of cliffs, roughly 3.5 by 2.5 kilometres, rising straight out of the Philippine Sea some 358 kilometres south of Tokyo; inside it lies the Ikenosawa caldera, about a kilometre and a half across, and in the middle of that green bowl stands Maruyama, a neat secondary cone a little over 200 metres high. The island is built from the overlapping remains of at least four submarine calderas, and its highest point, Otonbu, reaches 423 metres on the rim. From up there the whole structure reads at a glance: sea, cliff, forested crater floor, and the small round summit sitting in it like a stone in a cupped hand.

The beauty has a hard history behind it. Between 1781 and 1785 Aogashima erupted repeatedly; in 1783 lava forced every household off the island, and the great eruption of 1785 killed somewhere between 130 and 140 of the 327 islanders. The volcano has been quiet since the eighteenth century, but it is still classed as active, and its warmth is everywhere: steam vents, known locally as hingya, breathe out of the crater floor. Islanders cook over them, warm themselves in a small sauna fed entirely by volcanic heat, and since 1999 have run a village salt works where Kuroshio seawater is evaporated slowly over the steam for weeks.

Today the island is a village of around 170 people, the least populous municipality in Japan, administered from Hachijō Subprefecture as part of Tokyo. Much of the island is left to forest and birds, and it is listed as an Important Bird Area for Japanese woodpigeons, grasshopper warblers and Izu thrushes. What makes a visit memorable is the change of scale: from the rim, the caldera floor looks like a separate small world, and down on that floor, beside the steaming ground and the rounded flank of Maruyama, the cliffs close in on every side, so that the sea, though only a few hundred metres away, disappears completely.

Getting there

Aogashima lies about 64 km south of Hachijō-jima, which is the base for every journey. Hachijojima Airport (HAC), roughly 73 km away, has daily ANA flights from Tokyo Haneda taking around 50 minutes. From Hachijō-jima the Tokyo Ai-land Shuttle helicopter, the only scheduled helicopter service in Japan, makes the hop in about 20 minutes but carries only nine passengers, so seats are booked well ahead. The alternative is the cargo-passenger ship Kanju-maru, which sails once a day except Sundays; because the island's small harbour faces the open Kuroshio swell, sailings are frequently cancelled, and a spare day or two in the schedule is wise.