Himi Tunnel

Himi Tunnel: A Taisho-Era Engineering Marvel on the Historic Nagasaki Kaido

Tucked beneath the storied Himi Pass in eastern Nagasaki City, the Himi Tunnel stands as a striking monument to Japan's early automotive age. Completed in 1926 during the final year of the Taisho period, this 642-meter concrete road tunnel was once the largest of its kind in the country. Nearly a century later, it continues to carry traffic along a prefectural route, its ornamental portal facades still projecting the dignified engineering aesthetic of a bygone era. For visitors with an interest in modern heritage, historic highways, and the layers of transportation history that shaped Nagasaki's connection to the rest of Japan, the Himi Tunnel offers a compelling and little-known destination.

A Gateway Through Centuries of History

The Himi Pass, known in Japanese as Himi Toge, has been the critical land gateway into Nagasaki for centuries. During the Edo period (1603–1868), the Nagasaki Kaido highway connected the city of Nagasaki to Kokura in present-day Kitakyushu, spanning roughly 228 kilometers. Of all the passes along this route, Himi Pass was the most formidable, earning it the nickname "the Hakone of the West" — a comparison to the famously steep Hakone Pass on the Tokaido highway near Tokyo.

Travelers of all kinds crossed this pass: Dutch trade envoys journeying to Edo for their required audiences with the shogun, samurai lords overseeing Nagasaki's defenses, scholars like Philipp Franz von Siebold, and even exotic animals such as elephants and camels being transported to the capital. The pass was so steep that teahouses sprang up at its summit where exhausted travelers could rest and gaze out at the city of Nagasaki and Mount Inasa beyond.

In 1882, during the Meiji period, a new road was carved through the pass by cutting down the summit by approximately 33 meters. This "Meiji New Road" was one of Japan's earliest toll roads, charging five rin per person and two sen for a rickshaw. However, as automobiles began to appear in Japan during the Taisho period (1912–1926), even this improved road proved inadequate for motorized traffic. A more radical solution was needed.

Construction and Engineering Significance

In 1924, Nagasaki Prefecture commenced construction of a full-scale road tunnel beneath the Himi Pass. After two years of work and an investment of approximately 477,000 yen — a substantial sum at the time — the Himi Tunnel was completed and opened to traffic in April 1926.

At 642 meters in length and 7.4 meters in width, it was the largest road tunnel in Japan at the time of its completion. The tunnel was built as a concrete structure with a horseshoe-shaped cross-section, and remarkably, it already provided a nearly complete two-lane configuration — a forward-looking design at a time when automobile ownership was still in its infancy in Japan.

The tunnel's most celebrated feature is its pair of ornamental portal facades, one at each end. These portals feature stone-clad arch surrounds framing the horseshoe-shaped entrance, flanked by classical pilasters and topped with decorative cornices. Grooved joint lines etched into the concrete walls add further visual refinement. The overall design reflects the Taisho-era aesthetic sensibility, which blended Western classical architectural vocabulary with Japanese engineering pragmatism. This decorative approach to tunnel portals was characteristic of an era when civil engineers regarded infrastructure not merely as functional necessity but as an expression of civic pride and modernity.

Why It Was Designated a Registered Tangible Cultural Property

In February 2002, the Himi Tunnel was officially registered as a national Registered Tangible Cultural Property (building) by the Japanese government. The registration recognized several key values.

First, the tunnel represents a pioneering achievement in Japanese road tunnel engineering, built at the very dawn of the automotive era. It is a rare surviving example of a large-scale Taisho-period road tunnel that remains in active use. Second, the ornamental portal designs are considered exceptionally fine examples of early 20th-century civil engineering aesthetics, preserving the decorative sensibilities of their time. Third, as part of the historic transportation corridor through the Himi Pass, the tunnel is inseparable from the broader cultural landscape of the Nagasaki Kaido, one of Japan's most historically significant highways.

The fact that the tunnel continues to function as an active roadway — now carrying traffic on Nagasaki Prefectural Route 116 — adds to its significance as a living piece of infrastructure heritage rather than a static museum exhibit.

Highlights and What to See

The Taisho-Era Portal Facades

The tunnel's most photogenic feature is its pair of ornamental portals. Visitors approaching from either the Honkawachi (west) or Susukizuka (east) side will be struck by the dignified stonework and classical proportions of these entrance structures. The design DNA of these portals was later echoed in the newer Shin-Himi Tunnel on the adjacent bypass road, creating an intriguing visual dialogue between old and new engineering.

The Registered Cultural Property Memorial Stone

Near the eastern portal on the Susukizuka side, a memorial stone commemorates the tunnel's designation as a Registered Tangible Cultural Property. This makes a convenient starting point for exploring both the tunnel itself and the adjacent historic trails up to the Himi Pass.

The Old Nagasaki Kaido Trail

From the eastern portal of the tunnel, a steep trail leads up to the original Edo-period Himi Pass. Along the way, visitors can find the Susukizuka Haiku Monument, erected in 1813 to honor the 120th anniversary of the poet Matsuo Basho and the 110th anniversary of his disciple Mukai Kyorai, who was born in Nagasaki. The place name "Susukizuka" (Pampas Grass Mound) itself derives from one of Kyorai's poems about parting at this pass.

The Himi Pass Checkpoint Ruins

Further along the old trail, remnants of the Edo-period checkpoint that once controlled passage over the pass can be found. From the summit, on a clear day, visitors are rewarded with views of Nagasaki city and Mount Inasa — the same panorama that greeted weary travelers for centuries.

Surrounding Attractions

The Himi area offers several points of interest that complement a visit to the tunnel.

The Nagasaki Penguin Aquarium, located nearby in the Himi district along the shores of Tachibana Bay, is one of Japan's most specialized aquariums, housing nine of the world's eighteen penguin species. Its breeding techniques are internationally recognized and have been documented in overseas literature as the "Nagasaki Method."

The Hotarujaya (Firefly Teahouse) area, at the western end of the old Nagasaki Kaido route through the city, marks the traditional farewell point where Nagasaki residents would see off departing travelers. The tram terminus here provides convenient access to the city center.

For those interested in Nagasaki's broader history, the city center offers world-class destinations including the Nagasaki Atomic Bomb Museum, Peace Park, Glover Garden, Dejima, and the churches associated with the UNESCO World Heritage "Hidden Christian Sites in the Nagasaki Region."