Iya Valley

祖谷渓いやけいIya-kei

Vine bridges and hidden villages in Shikoku's mountains

The Iya Valley (Iya-kei) is a deep, forested gorge in the mountains of western Tokushima Prefecture, part of the city of Miyoshi. Long one of Japan's most isolated regions, it is known for bridges woven from vines, hamlets clinging to steep slopes and the legend that defeated Heike warriors hid here.

Quasi-national park · 1964

Overview

The Iya River rises on the slopes of Mount Tsurugi and flows west through the Shikoku Mountains to join the Yoshino River near Ōboke. Along much of its course it runs hundreds of metres below the road in a steep V-shaped valley, whose sides are so steep that farms and houses are built on terraces cut into the slopes.

The valley was reached by a road only in the 20th century, and its isolation preserved an older way of life: thatched farmhouses, buckwheat and millet farming, and bridges made from the vines of the hardy kiwi (shirakuchikazura). The Kazurabashi at Nishi-Iya is the best-known of these bridges and a designated Important Tangible Folk Cultural Property.

The valley is often divided into Nishi-Iya (west) with the vine bridge and the gorge viewpoints, and Higashi-Iya or Oku-Iya (east), deeper in the mountains towards Mount Tsurugi, where a pair of vine bridges and the preserved hamlet of Ochiai stand.

Landscape and formation

The Iya River has cut deeply into crystalline schist of the Sanbagawa metamorphic belt, lifted along the Median Tectonic Line to the north. The gorge walls drop some 200 metres from the road to the river in places. Nearby, the Yoshino River carves the related Ōboke and Koboke gorges through the same rocks.

Highlights

Kazurabashi
祖谷のかずら橋Iya no Kazurabashi
Suspension bridge of about 45 m woven from vines, rebuilt every three years, an Important Tangible Folk Cultural Property.
Oku-Iya Double Vine Bridges
奥祖谷二重かずら橋Oku-Iya Nijū Kazurabashi
The 'husband and wife' bridges side by side deep in the eastern valley, with a hand-pulled cable cart.
Ochiai hamlet
落合集落Ochiai shūraku
Village of farmhouses and fields on a slope with a height difference of about 390 m, an Important Preservation District for Groups of Traditional Buildings.
Peeing Boy statue
小便小僧Shōben Kozō
Small statue on a rock above a 200 m drop, recalling local boys' tests of courage.

Ecology

Steep forests of cedar plantation and natural broadleaf woodland cover the slopes, colouring in November. The clear river holds amago trout, and the valley's upper reaches border the subalpine forests of Mount Tsurugi.

Flora

Shirakuchizuru
シラクチカズラshirakuchikazura
Hardy kiwi vine, the material of the vine bridges.

Fauna

Amago trout
アマゴamago
Red-spotted trout of the clear mountain streams, grilled on skewers as a local dish.

Culture

Local tradition holds that survivors of the Taira (Heike) clan fled into Iya after their defeat in 1185 and lived here hidden from the victorious Minamoto; the vine bridges are said to have been designed so they could be cut quickly. Iya soba, made with coarse local buckwheat, and dekomawashi, skewers of potato, tofu and konnyaku grilled over an open hearth, are the valley's traditional foods.

Heike legend
平家落人伝説Heike ochiudo densetsu
Tradition of Taira refugees settling in the valley, recalled at the Heike Yashiki house in Higashi-Iya.
Iya soba
祖谷そばIya soba
Short, thick buckwheat noodles with little or no wheat binding.

History

1185
According to local legend, Taira survivors flee into Iya after the Battle of Dan-no-ura.
1955
The Kazurabashi is designated an Important Tangible Folk Cultural Property.
1964
Tsurugisan Quasi-National Park is designated.
1968
The Peeing Boy statue is placed on the cliff above the gorge.
2005
Ochiai becomes an Important Preservation District for Groups of Traditional Buildings.
2006
Ikeda, Nishi-Iyayama, Higashi-Iyayama and other towns merge to form the city of Miyoshi.

Through the seasons

Spring

Fresh green from April; mountain vegetables in local cooking.

Summer

Cool riverside, rafting on the Yoshino at Ōboke.

Autumn

Autumn colour in November, the valley's busiest season.

Winter

Snow on the higher roads; some facilities in Oku-Iya close.

Routes and trails

Iya Valley road
Old road high above the gorge from Ōboke to Nishi-Iya, with viewpoints and the Peeing Boy statue.
Oku-Iya and Mount Tsurugi
Road east through Higashi-Iya to the double vine bridges and the trailhead at Minokoshi.

Practical notes

Ōboke Station on the JR Dosan Line is the gateway; buses run into the valley, but a car is by far the most practical.
Roads are narrow and winding with sheer drops; allow plenty of time.
Crossing the vine bridge takes a steady step – gaps between the slats are wide.

Frequently asked questions

How do you get to the Iya Valley?

By JR Dosan Line to Ōboke Station, then by bus or car into the valley; a car is recommended.

Is the Iya vine bridge safe?

Yes. It is reinforced with steel cables and rebuilt every three years, although the gaps between the slats make the crossing feel precarious.

Why is the Iya Valley associated with the Heike?

Legend holds that Taira clan survivors hid in the remote valley after their defeat in 1185.

When is the best time to visit?

November for autumn colour, or spring to early summer for fresh green and fewer visitors.