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Kirosan Observatory Park

KirosanKengo KumaKurushima StraitShimanami KaidoImabari

Ehime · Imabari

34.1153°N, 133.0373°E

Kirosan is a 301-metre hill at the southern tip of Oshima, looking down on the Kurushima Strait — one of the three fastest tidal channels in Japan, where the current runs at up to ten knots and visibly boils — and on the Kurushima Kaikyo Bridge, the first triple suspension bridge in the world at four kilometres long.

The observatory is by Kengo Kuma and is designed to be invisible: the building is buried in the hilltop with trees planted over it, so that from below the hill looks unaltered and you only find the structure by walking into a cut in the ground. You come out onto a concrete deck with the strait, the bridges and, on clear days, Mt. Ishizuchi in front of you. Parking is free and the shop sells a salt ice cream that is locally famous.

Essential Information

Opening Hours

Park open at all times | Shop keeps daytime hours

Closed: Open year-round

Entrance Fee

Free | Free parking

Best Season

Year-round | Clear days for Mt. Ishizuchi; check tides for the strait

Visit Duration

45–60 minutes

Getting There

Access Information

Minamiura 487-4, Yoshiumi-cho, Imabari, on Oshima. About 15 minutes by car from Oshima-Kita IC on the Nishiseto Expressway, or about 60 minutes from Nishiseto-Onomichi IC. Free to visit, with a large free car park. A shop at the park entrance sells Imabari goods and the local salt ice cream.

Insider Guide

Premium

**The building is buried on purpose.** Kuma set the structure into the hilltop and planted over it so the silhouette from below is unchanged. Approach on foot from the car park and notice that you cannot see it until you are in it. **Go for the tide, not just the bridge.** The Kurushima Strait runs at up to ten knots and the whirlpools are visible from the deck. Slack water is much less impressive — tide tables are worth checking. **Clear days show Ishizuchi.** The highest mountain in western Japan appears across the water in good visibility. **It is a cycling stop.** The Shimanami Kaido cycle route passes below and the climb to Kirosan is a well-known optional detour for riders. **Eat the salt ice cream.** Imabari makes salt and the shop at the entrance sells it in soft serve. It is better than it sounds and everyone gets one.

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