Kanmon Strait

The Kanmon Strait separating Honshu from Kyushu narrows to just half a kilometer of navigable width at its tightest point, with currents reaching 11 knots and an S-shaped bend that challenges pilots to this day. The strait's history spans a twelfth-century naval battle that ended with a child emperor drowned in his grandmother's arms, to Miyamoto Musashi's famous duel on Ganryujima Island, to the 1863 Shimonoseki Campaign when Choshu domain cannon fire on an American merchant ship triggered retaliatory naval strikes from four Western nations. Around 600 vessels still pass through daily.