Sakurajima

Every port has a landmark. Kagoshima has a neighbour that occasionally throws things at it.

Sakurajima stands 1,117 metres high, about four kilometres across the bay from the city centre, and it has been continuously active since October 1955. The Japan Meteorological Agency has logged its explosions month by month ever since. Most are small bursts of ash.

The bigger thing underneath

The startling fact is not the volcano. It is that Sakurajima is the small child of something far larger: it grew inside the southern rim of the Aira caldera, a collapsed structure roughly 17 by 23 kilometres formed by a colossal eruption some twenty-two to twenty-nine thousand years ago. Kagoshima Bay — the water your ship is floating on — is largely that caldera. The mountain everyone photographs sits on the edge of a far bigger system that is still inflating.

The eruption that ended an island

Strong earthquakes began on 11 January 1914; the eruption itself started the next day. Fifty-eight people died — thirty-five in the earthquakes, twenty-three in the eruption — and most of the island's twenty-two thousand residents got out by boat.

Then, on 30 January 1914, the lava flow on the east flank filled the strait and welded Sakurajima to the mainland. It has not been an island since. The name — 桜島, "cherry blossom island" — is now a fossil of the geography that existed before your great-grandparents were born.

At Kurokami, a three-metre shrine gate was buried until only about a metre of its top crossbeam showed. Villagers wanted to dig it out. The village mayor said no — leave it, as a warning.

It is still there, still buried, free to visit on the island's east side. It remains Japan's largest explosive eruption of the twentieth century.

What living here is actually like

A city of nearly six hundred thousand people sits about ten kilometres from an erupting crater, and it has made the ash administrative. Residents sweep ash into municipally issued yellow bags and leave them at neighbourhood collection points — there are thousands of designated ash collection points across the city, and ash is collected separately from ordinary refuse. In 2011, the record year, roughly 5,900 cubic metres of bagged household ash was collected in the urban area alone.

Elementary school children wear hard hats to and from school against falling ash and pumice. The daily ashfall forecast is checked the way other cities check rain — it decides whether you hang laundry, open a window, or wash the car. Concrete shelters dot the island, and drills have run since 1970.

The world's largest radish and its smallest orange

The volcanic soil grows two absurdities. The Sakurajima daikon holds a Guinness record at 31.1 kilograms with a 119-centimetre circumference — the largest radish on earth. And the Sakurajima komikan, four to five centimetres across, is held to be the world's smallest mandarin. One island, both records, same dirt.

Crossing, and what to do over there

The ferry runs from about 4:30 until 23:30, every day of the year — every twenty minutes by day — and takes about fifteen minutes for ¥250. No booking exists or is needed. It is a working commuter service: cars, delivery vans, high-school students. There is a famous udon counter on board, and the local custom is to order the moment you board and hand the bowl back as the ramp drops.

On the far side, the Nagisa Lava Trail runs across the 1914 flow, and a 100-metre free foot bath faces the strait. Higher up, the Yunohira Observatory at 373 metres is the closest visitors may go — climbing Minami-dake is prohibited, and the routine alert level is a standing "do not approach the summit."

From a cruise berth, the crossing and the lava trail fit comfortably into a five-hour stop ashore with margin to spare. It is the single thing this port has that no other port in Japan can offer.