... carries a railway under the Tsugaru Strait, which separates the Japanese islands of Honshu and Hokkaido. By some quirk of linguistics, its name comes from the initial characters of the names of the cities at either end of it – Aomori and Hakodate.
The Seikan is the world's longest undersea tunnel; it's about 2.5 miles (4 km) longer than the Channel Tunnel. But its undersea section, at 14.5 miles (23.3 km) is almost ten miles (16 km) shorter than that of the Chunnel.
© Haydn Thompson 2017