Mitsubishi owned Battleship Island, a coal town of concrete blocks emptied in 1974.
In 1890 Mitsubishi bought Hashima, an islet off Nagasaki with coal under the seabed, and from 1916 stacked it with concrete apartment blocks. During the war at least 800 Koreans were sent there as forced laborers, and 134 reportedly died. Mitsubishi closed the mine in 1974, and within months the island was empty.
Mitsubishi on Brandseum