Shimabara

The first thing Lia did in Shimabara was crouch over a drain. Not a drain, it turned out, but one of the spring-fed channels that run alongside the streets in the old samurai quarter — and in it, unhurried and enormous, drifted carp the size of my forearm. Orange, white, mottled gold, swimming through what for all the world looked like a roadside gutter in the middle of a residential street. A woman came out of her house, saw us gawping, and told us with obvious pride that the water was so clean the fish had lived there for years, fed by the neighbourhood. This, we learned, is Shimabara’s whole character: a town so lousy with pure springwater — melt from Mount Unzen above — that it lets carp live in the streets and calls it normal.

The carp-swimming streets

The street they call Shimeigawa, in the shadow of the old town, is the one to find. A clear channel runs down its length, thick with koi, crossed by little stone slabs, flanked by traditional houses. We spent a ridiculous amount of time just following the fish, watching them nose against the current beneath overhanging ferns. At one point an old man was washing vegetables in a stone basin fed by the same spring, entirely unbothered by the carp nosing at the runoff. Lia bought a small bag of fish food from an honesty box and fed them, and for a moment the water boiled with orange backs. It costs nothing and it is one of the gentlest half-hours we spent anywhere in Japan.

The white castle

Shimabara Castle rises white and steep-walled at the town’s centre, a five-storey keep reconstructed on the site of the original, which loomed over one of Japan’s great rebellions — the Christian-led Shimabara uprising of the seventeenth century. The exhibits inside lean heavily into that grim history of persecution and siege, with hidden crosses and fumi-e images that suspected Christians were made to trample. But the pleasure of the place, honestly, is the view from the top: the town spread out in tiled rows, the flat blue of the Ariake Sea on one side, and the green shoulders of Unzen rising on the other. Lia noted that a fortress built for a bloody purpose now mostly serves to give tourists a nice panorama, and there was something both cynical and hopeful in that.

Unzen, the mountain that buried the coast

You cannot spend a day in Shimabara without the volcano asserting itself. In the early 1990s Mount Unzen erupted, and pyroclastic flows and mudslides buried houses along the lower slopes. At the preserved site near Mizunashi, we walked among homes half-swallowed by hardened debris — a second storey poking out of grey rock, a roof at ground level. It is a sobering, quiet place, and the townsfolk have chosen to keep it visible rather than clear it away, a monument to what the beautiful mountain can do. Later we soaked in an onsen fed by that same volcanic system, the water hot and faintly sulphurous, and I thought about how the thing that had buried the coast also gave the town its carp-clear springs. Japan is full of that kind of arithmetic.

Getting There

Shimabara sits on the eastern side of the Shimabara Peninsula in Nagasaki Prefecture, on the island of Kyūshū. From Nagasaki city you can take a train to Isahaya and change to the private Shimabara Railway, a charming single line that trundles along the coast to Shimabara in a little over an hour. Alternatively, a ferry crosses the Ariake Sea from Kumamoto, which makes Shimabara a natural stop if you’re island-hopping between the two. The town itself is small and walkable — castle, carp streets and hot springs are all close — but a car helps for reaching the Unzen eruption memorial and the mountain onsen resorts higher up.