What strait separates the Japanese islands of Honshu and Hokkaido?

The Tsugaru Strait separates Japan’s Honshu and Hokkaido islands and connects the Sea of Japan with the Pacific Ocean.

It stretches between northern Honshu, particularly the Tsugaru Peninsula in Aomori Prefecture, and southern Hokkaido’s Matsumae Peninsula. At its narrowest point, the strait is about 19.5 kilometres wide. The Seikan Tunnel, one of the world’s longest undersea railway tunnels, passes beneath this section and links the two islands by rail.

The waterway has also influenced Japanese transport and history. Ferry services have operated across it, but the sinking of the ferry Tōya Maru on 26 September 1954 caused 1,172 deaths in one of Japan’s worst maritime disasters. Earlier Western maps sometimes called the strait the Strait of Sangar.

It is sometimes confused with the La Pérouse Strait, also called the Sōya Strait, which separates Hokkaido from Russia’s Sakhalin Island. The Korea Strait, meanwhile, lies southwest of Japan between Kyushu and the Korean Peninsula.