Tokushima

Water moves between the Inland Sea and the Pacific through a narrow strait, and the difference in level at either end is what spins it. That means the spectacle is governed by the moon: there are a few strong windows each day, they shift forward daily, and on some days they fall at times no visitor would choose. Arriving mid-afternoon because that is when you happened to be free is the way most people end up looking at ordinary water.

Check the published tide times before you fix anything else about the day, then build the rest of it around them — the boats and the walkway both run all day, but only some of those hours are worth the trip. Spring and autumn tides are stronger than neap ones, so the same hour is not equally good in every week of the month.

Two days. Tokushima's two draws are the whirlpools in the strait at Naruto and the Iya valley in the mountainous interior, and they are at opposite ends of the prefecture in every sense — one is an hour from the city on a good road, the other is three hours into a gorge on a bad one.

Naruto is about an hour from Tokushima City by bus, and the whirlpools run to a tide table rather than a timetable, so the visit has to be planned around the water rather than the day.

The Iya valley is the serious commitment: vine bridges, a gorge, hot springs reached by cable car down a cliff, and villages with straw figures sitting in them. It is two to three hours from the city and wants an overnight. Three days does both properly; two does one well and the other badly.

A car for the valley, public transport for the coast. Naruto is a straightforward bus from Tokushima City, and the city itself is walkable. That is one day sorted without driving.

The Iya valley is different: the railway reaches Oboke at the mouth of the gorge and the buses beyond it are few, the roads are narrow and winding, and the distances between the vine bridges, the villages and the hot springs are real. Hire a car or accept that you will see one thing. Note also that this is one of the more demanding drives in western Japan — single-lane sections with passing places above a drop.

The first stretch of the eighty-eight temple circuit that loops the island lies in this prefecture, which is why you will pass people in white cotton and conical hats on ordinary roadsides, sometimes far from anything. They are walking a route that takes weeks, and they are travelling rather than performing.

Two things follow. First, the temples at this end are busier and better set up for visitors than those further round, so if you want to see what the circuit is, this is the easiest place to look. Second, the courtesies are simple and worth knowing: give way on narrow paths, do not photograph people close-up without asking, and keep back from the halls while someone is reciting. Small roadside huts and benches along the route exist for walkers, not as picnic spots.

There is no shinkansen on Shikoku. From Osaka the fastest route is a highway bus over the Akashi and Naruto bridges, roughly two and a half hours to Tokushima; by rail you take the Sanyo Shinkansen to Okayama, then the Marine Liner and a change. Tokushima Airport is about half an hour from the city. Inside the prefecture the JR Kotoku and Tokushima lines cover the coast and the Yoshino river valley, but the Iya valley is the hard part — the Yodo line reaches Oboke, and buses from there into the gorge run only a few times a day. For Iya and the Ochiai terraced village, drive, on roads that are narrow and single-track in places.

The Awa Odori dance festival in mid-August fills Tokushima City completely; it is one of the great festivals in the country and a terrible week to arrive without a booking. Either come for it deliberately or come at another time.

The Iya valley in winter is cold, the roads carry snow and ice, and some of the smaller ones become genuinely unsafe. Late summer brings typhoons to this Pacific-facing island and the mountain roads close. Spring and autumn are the windows, with the gorge foliage in November being the best of it.

Tokushima ramen comes in a dark pork-and-soy broth with sliced pork belly and, characteristically, a raw egg cracked on top and rice ordered alongside. Sudachi, a small green citrus, is grown here almost exclusively and squeezed over nearly everything from grilled fish to noodles from August to October. Handa somen is thicker than the Miwa style and made along the Yoshino river. Naruto's fast tidal water grows dense wakame seaweed harvested in late winter, and the same strait gives its name to the swirl-patterned fish cake in ramen bowls.

Awa Odori runs August 12–15 and accommodation across the region is booked months out; it is the single reason many people come. The whirlpools at Naruto are largest around the spring and autumn equinox tides and at new and full moons, and they follow a daily timetable — check the forecast before booking a boat, because a mistimed trip sees nothing. Summers are hot above 33°C and this coast is exposed to September typhoons. The Iya valley is cooler and sees light snow in January; its autumn colour peaks in early November. The rainy season in June is heavy in the mountains.

A first visit is Naruto and the city, timed to the tide. The whirlpools form in the strait between Shikoku and Awaji four times a day and their scale depends on the moon; there is a boat that takes you into them and a glass-floored walkway on the bridge above. Tokushima City itself has an indigo-dyeing tradition you can try and a mountain with a ropeway over the delta.

A second visit is the Iya valley, with a car and two nights. Vine bridges you cross on foot over a river, a hot spring you reach by cable car down the side of a gorge, and villages so depopulated that residents have made life-sized straw figures to sit in the empty houses. It is the most remote-feeling place in Shikoku and it is three hours from a ferry to Kansai.