Gunkanjima

Gunkanjima, or Hashima, lies about forty minutes by boat from Nagasaki. The name means battleship island. It is artificial: a reef built out with reclaimed ground, walled in on every side against the sea, and filled with blocks of reinforced concrete. Seen from the water the outline was thought to resemble the warship Tosa, and the nickname stuck.

There was coal under the seabed here. Worked together with the mine on neighbouring Takashima, it fed the industries of a country that was industrialising fast, and the island grew upward because there was nowhere else to grow.

At its fullest, in 1960, about 5,300 people lived on Hashima, which made it the most densely populated place in Japan. Everything they needed was on the island: primary and junior high schools, a hospital, shops, a cinema, a pachinko parlour.

When industry turned from coal to oil the mine lost its purpose. It closed in 1974, the islanders left, and the island has been empty since.

Landing was allowed again in 2009, on a marked walkway that keeps visitors clear of the ruins. The island is part of the World Heritage listing for the sites of Japan's industrial revolution.

The island can only be visited on a landing tour run by one of the boat companies of Nagasaki. Landing depends on wind and sea and is decided on the day; when it is not possible the trip becomes a cruise around the island.