The Kanmon Kaikyo Museum (Kaikyokan) is Shimonoseki's world-class aquarium and strait heritage centre — home to the only whale shark exhibit in western Japan and a tunnel aquarium running beneath a living reef. A rare, immersive encounter with the biodiversity of the strait itself.
What to expect
Enter through galleries dedicated to the ecology and human history of the strait, then descend to the 105-metre walk-through acrylic tunnel surrounded by thousands of fish. The dedicated fugu exhibition explains the meticulous licensing system that makes this deadly delicacy safe — and delicious. Upstairs, the outdoor terrace delivers unobstructed views of the Kanmon Bridge and passing tankers in one of the world's busiest straits. Dolphin and penguin shows run several times daily in the outdoor theatre.
Good to know
A 10-minute walk from the Shimonoseki cruise pier along the attractive waterfront promenade. Open daily 09:30–17:30 (last entry 17:00). Book tickets online at kaikyokan.com to avoid queues. Allow 2–2.5 hours; pair with Karato Market (5 min walk) for a full morning.