Kase Tunnel: A Meiji-Era Stone Gateway Through the Mountains of Hagi
Tucked away in the wooded hills between the former castle town of Hagi and the village of Akiragi in Yamaguchi Prefecture stands a remarkable survivor of Japan's early modernization. The Kase Tunnel (Kase Zuidō) is a hand-built stone road tunnel completed in the Meiji era, and to this day it remains the oldest road tunnel in Yamaguchi Prefecture. Walking beneath its weathered ashlar arch is like stepping into a quiet pocket of the 1880s, when Japan was rebuilding its road networks in a Western style and the people of Hagi were rebuilding the fortunes of their town.
An Overview of the Tunnel
The Kase Tunnel pierces the steep Kasega-saka Pass that has long separated Hagi from the inland route toward Ogori (today part of Yamaguchi City). Its dimensions are modest by modern standards but were impressive for their time: a length of about 182 metres, a width of about 4.2 metres, and a height of about 3.9 metres. The arch and walls are lined entirely with carefully cut andesite stone, a construction technique that gives the interior its distinctive cool, cathedral-like feel. Above the northern portal, a stone tablet carved with the characters "Kase Zui" (鹿背隧) is set neatly into the band of dressed stones.
The tunnel was registered as a National Registered Tangible Cultural Property of Japan on 8 July 1999, in recognition of its historical and architectural value. Despite being more than 130 years old, it is still an active road, used quietly by local drivers and the occasional curious traveller.
Historical Background: Hagi After the Castle Town
To appreciate the Kase Tunnel, it helps to understand the moment in which it was built. Hagi had been the seat of the powerful Mōri clan and the political heart of the Chōshū Domain — the very domain whose young samurai, including Yoshida Shōin, Itō Hirobumi, and Yamagata Aritomo, played leading roles in the Meiji Restoration of 1868. Yet only a few years after the Restoration, the prefectural seat was relocated from Hagi to Yamaguchi, leaving the old castle town with diminished political weight and an uncertain economic future.
In response, the people of Hagi looked to improved transport as a means of revival. The road connecting Hagi with Ogori on the San'yō (Inland Sea) side of the prefecture was a vital artery in the so-called San'in–San'yō connecting route, and its modernization was seen as a key step in restoring the prosperity of the city. The Kase Tunnel was one of the most ambitious works of that programme. Construction began in 1883 under the direction of Yamaguchi Prefecture, and the tunnel was officially completed in 1886.
Why the Kase Tunnel Was Designated a Cultural Property
The Kase Tunnel earned its place on the national register of cultural properties for several intertwined reasons.
The First Western-Style Stone Tunnel in Yamaguchi
The Kase Tunnel is recorded as the very first Western-style stone road tunnel built in Yamaguchi Prefecture. Before its completion, travellers crossing the Kasega-saka Pass had to negotiate a steep, winding mountain path. The introduction of a properly engineered tunnel, with a stone arch and dressed ashlar walls, represented a leap forward in civil engineering for the region.
A Rare Example of 1880s Stone Tunnel Engineering
Stone-clad road tunnels from the 1880s are extremely rare in Japan, and the Kase Tunnel stands out even among them for its length and the quality of its workmanship. Its 182-metre run is exceptionally long for a stone-lined tunnel of that decade, making it a precious example of the brief moment when Japanese stoneworkers and Meiji-era engineers combined traditional craft with imported European tunnelling techniques.
A Symbol of Hagi's Hopes for Revival
The tunnel was more than a piece of infrastructure. It was built to embody the hopes of a town determined to remain relevant after the loss of its political role. As a public work undertaken with significant local effort and prefectural investment, it stands today as a tangible reminder of the resilience and ambition of the people of early Meiji Hagi.
Highlights and What to See
The Stone Portals
The most photogenic features of the Kase Tunnel are its two stone portals. Each is built of carefully cut andesite blocks arranged in an arch, with the northern entrance bearing the stone plaque inscribed "Kase Zui." The colour of the stone, mellowed by more than a century of damp mountain air, and the moss creeping along the edges give the portals a quietly dignified, almost ruin-like beauty.
The Stone-Lined Interior
Step inside and the modern world fades away. The walls and arch are entirely faced with cut stone, and L-shaped iron fittings are still attached to the masonry — silent witnesses to the practical fittings of a Meiji-era road. The air is cool and a little damp, and the sound of footsteps echoes in a way that wood or concrete tunnels rarely allow.
The Approach Through the Hagi-Ōkan Landscape
The narrow approach roads on both sides of the tunnel are part of the historic Hagi-Ōkan, the old highway that the Mōri lords once travelled on their journeys to and from Edo. Mossy stone pavements, dense trees, and the occasional stone marker bring the past close to the surface. Walkers exploring the Hagi-Ōkan often pass over the tunnel as part of a longer hike, while drivers can reach it by a short, winding detour from the modern prefectural road.
Surrounding Attractions
The Kase Tunnel is well placed for travellers who want to combine industrial heritage with the wider treasures of Hagi.
- Michi-no-Eki Hagi-Ōkan — a roadside station only a short walk from the tunnel, with a small museum on the Hagi-Ōkan highway, local food, and souvenirs.
- Hagi Castle Town — a historic district of white-walled samurai residences, merchant houses, and citrus-tree gardens, registered as a UNESCO World Heritage component of the Sites of Japan's Meiji Industrial Revolution.
- Shōkasonjuku Academy — the modest school where Yoshida Shōin taught the young thinkers who would help shape modern Japan, also part of the World Heritage Site.
- Akiragi Post Town — a charming former post town along the Hagi-Ōkan, with old bridges, stone monuments, and quiet streets to wander.
- Hagi-yaki Pottery Kilns — workshops producing the famously understated tea-ware that has been treasured by Japanese tea practitioners for over four centuries.
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Q&A
- Is the Kase Tunnel open to visitors and can I drive through it?
- Yes. The tunnel is still in use as a public road and is freely accessible. There is no admission fee. The approach roads are narrow and winding, so drivers should take care, especially when meeting oncoming vehicles. Walking through the tunnel is a memorable experience and is recommended for those who want to take their time with the stonework.
- How old is the tunnel exactly?
- Construction began in 1883 (Meiji 16) and the tunnel was completed in 1886 (Meiji 19). It has therefore been in service for more than 130 years, making it the oldest road tunnel in Yamaguchi Prefecture.
- What is the best way to reach the Kase Tunnel?
- By car, it is roughly 15 minutes from Higashi-Hagi Station, just behind the former Hagi toll road (Prefectural Route 32). A convenient strategy is to park at Michi-no-Eki Hagi-Ōkan and walk the short distance to the tunnel along the old road. Public transport access is limited, so a rental car or taxi is the most flexible option.
- Is there lighting inside the tunnel?
- The tunnel has very little lighting and can feel dark even during the day, which adds to its atmosphere but calls for a small flashlight or your phone's torch if you plan to walk through. Sturdy shoes are also a good idea, as the surface can be damp.
- Who built the tunnel?
- The project was carried out under the direction of Yamaguchi Prefecture, with stoneworkers from the local Hagi and Abu region as well as from Kuga in present-day Suō-Ōshima Town and Ajimu in Ōita Prefecture taking part in the construction. The combination of local and outside expertise was essential for handling the demanding stonework.
Basic Information
| Name | Kase Tunnel (Kase Zuidō) |
|---|---|
| Designation | National Registered Tangible Cultural Property (Building) |
| Registration Date | 8 July 1999 |
| Era | Meiji period; completed 1886 |
| Construction Period | Begun 1883 (Meiji 16), completed 1886 (Meiji 19) |
| Structure | Stone construction (andesite ashlar); single tunnel |
| Dimensions | Length approx. 182 m, width approx. 4.2 m, height approx. 3.9 m |
| Owner | Hagi City |
| Location | Tsubaki Kasegasaka — Akiragi Kasegasaka, Hagi City, Yamaguchi Prefecture |
| Access | About 15 minutes by car from Higashi-Hagi Station; near Michi-no-Eki Hagi-Ōkan, behind Prefectural Route 32 |
| Admission | Free; open at all times as a public road |
References
- 鹿背隧道 - 文化遺産オンライン (Cultural Heritage Online)
- https://bunka.nii.ac.jp/heritages/detail/136978
- 鹿背隧道 - 山口県の文化財 (Cultural Properties of Yamaguchi Prefecture)
- https://bunkazai.pref.yamaguchi.lg.jp/sp/bunkazai/summary.asp?mid=110157
- 鹿背隧道｜観光スポット｜【公式】山口県観光/旅行サイト おいでませ山口へ
- https://yamaguchi-tourism.jp/spot/detail_13830.html
- 国登録有形文化財 鹿背隧道 - Monumento
- https://ja.monumen.to/spots/12380
- 鹿背隧道｜観光情報｜おいでませ山口へ
- https://www.oidemase.or.jp/tourism-information/spots/13830
Last verified: 2026.05.10