Hakone Old Road

Stone Pavement on the Hakone Pass: Walking the Old Tōkaidō

In the summer of 1680, the Tokugawa shogunate paid 1,406 ryō of gold to lay broad slabs of andesite across the muddy track that climbed Hakone Pass. Travellers had been losing their footing here for generations. The bundles of hakone-dake bamboo first scattered along the route did little once the rains came, and the road remained a mire deep enough to swallow a man to the shins.

The result of that fortune in coin was the road known today as the Hakone Kyū-Kaidō, the Old Hakone Highway. It carried the Tōkaidō, Edo Japan's most important road, over the 846-metre Hakone Pass between Odawara and Mishima. Eight ri (about 32 km) of climbing, cresting, and descending earned it the nickname Hakone Hachi-ri, the Eight Ri of Hakone, and the reputation as "the steepest barrier under heaven."

Sections of the old paved road, lengths of cedar and pine avenue, and a handful of restored milestone mounds survive in Hakone Town, Mishima City, and Kannami Town. Together they form a single National Historic Site spanning two prefectures: a stretch of working road frozen at the moment a Tokugawa-era traveller might have rested on the stones to catch his breath.

The Building of Hakone Hachi-ri

The Tokugawa shogunate opened the new Tōkaidō in Keichō 9 (1604) and routed it over Hakone rather than the older Ashigara crossing further north. From Mishima-juku at about 25 metres elevation, the road climbed to the pass at 846 metres before descending to Odawara-juku at roughly ten metres above sea level. Daimyō processions, post-runners, pilgrims to the Hakone Gongen, and any merchant heading between Edo and Kyoto had to cross it. The section from Mishima up to the Hakone Sekisho is called the Nishi-zaka, or western slope; the section running east from there down to Odawara is the Higashi-zaka.

Stone slabs did not arrive at once. For the first three-quarters of a century the shogunate tried lighter solutions, mainly fascines of hakone-dake, a slender mountain bamboo native to the pass. Heavy rain reduced these to slick mats over mud. In Enpō 8 (1680) the shogunate finally undertook the great expense of paving the road two ken wide, roughly 3.6 metres, in the manner that survives today. A further refurbishment came in Bunkyū 2 (1862) before the procession of the fourteenth shōgun, Tokugawa Iemochi, who travelled to Kyoto along this road.

Travel writers and ukiyo-e printmakers seized on Hakone as the dramatic centrepiece of the Tōkaidō. Hiroshige's Hakone in the Hōeidō series of 1833 shows a serpent of blue mountains rearing above a daimyō's procession. The Meiji-period schoolsong Hakone Hachiri, composed by Taki Rentarō to lyrics by Torii Makoto and first published in 1901, calls the pass steeper than the famous Hangu Barrier of China and describes the cedar avenue as dark even at midday.

Why It Was Designated

The Hakone Kyū-Kaidō was designated a National Historic Site on 22 September 1960 (Shōwa 35), at which point the listing covered only the paved sections and tree-lined avenues remaining in Hakone Town in Kanagawa Prefecture. The designation was meaningfully expanded on 18 October 2004 (Heisei 16), adding new districts on both slopes: in Hakone Town, the surviving stone pavement around Hatajuku and its pair of milestone mounds; in Kannami Town, paved sections and a milestone mound near the Settai Chaya; and in Mishima City, four further stretches of road and milestone mounds. Together the additions amount to 5.05 km of road and earthwork.

At the same time, a smaller historic site that had been independently designated decades earlier was rolled into the same listing. The Nishikida Ichirizuka, a pair of mounds standing on either side of the road 28 ri from Nihonbashi in Edo, had been recognised as a National Historic Site as early as 8 March 1922 (Taishō 11), one of the very first roadside features of the Tōkaidō to receive that status. It now belongs to the unified Hakone Kyū-Kaidō designation.

The site falls under designation criterion six, which covers "transport and communications facilities, civil engineering works for forests and rivers, production facilities, and other archaeological remains relating to economic and productive activity." The phrasing matters: this is not a temple, palace, or battlefield, but rather a piece of working infrastructure preserved for what it tells us about how Edo Japan moved people and goods.

What to Look For on the Road

The road has three signature features, and a walker who knows what to look for will see them all in the course of a single day.

The Stone Pavement

Excavations carried out before Mishima City's 1994–1997 restoration of five western-slope sections revealed exactly how the 1680 paving was built. Large slabs 30 to 70 centimetres across and 20 to 30 centimetres thick were laid in straight lines along the road edges; smaller stones were packed tightly between them. The road was set directly on the volcanic loam without any deep foundation, although clay and small pebbles were sometimes added beneath the stones on the steepest gradients. The stones themselves are flat-fracturing andesite, quarried from streambeds along the route such as the Raikō River.

One detail rewards close looking: small diagonal drainage channels were built across the road at intervals, using smaller stones on the upstream side and larger ones on the downstream side to create a slight step that diverted rainwater off the surface. At Shiromizu-zaka on the eastern slope, where original Edo-period stones remain in place, you can still pick out these channels in the path.

For their 1990s restoration of about two kilometres of paving in the Sasahara, Kami-Nagasaka, Sengen-daira, Koshimaki, and Gangō-ji districts, Mishima's restorers used andesite quarried from Nebukawa in Odawara, the closest geological match to the original.

The Milestone Mounds

Ichirizuka are pairs of earthen mounds, roughly ten metres in diameter, built at intervals of one ri (about 4 km) on both sides of the major Edo highways. Each was planted with a tree to make it visible from a distance. Travellers used them to gauge distance and to negotiate the fare for a porter or palanquin to the next stage.

Three pairs survive in good condition on the Hakone Kyū-Kaidō. The Hatajuku Ichirizuka, the 23rd from Nihonbashi, sits just above the village of Hatajuku at the foot of the famous seven switchback turns (nanamagari). Both mounds were fully restored in 1998 (Heisei 10), and at their proper size they make a striking pair flanking the entrance to the steepest part of the climb. The Sasahara and Yamanaka mounds on the western slope survive, as does the Nishikida Ichirizuka in Mishima, whose two mounds still carry mature enoki (Japanese hackberry) trees.

The Cedar Avenue

The most photographed stretch of the entire route is the Cedar Avenue at Moto-Hakone, where roughly 400 cedars line about 500 metres of road between the village and the Onshi-Hakone Park on a small peninsula in Lake Ashi. The trees are usually said to have been planted in Genna 4 (1618) on shogunal orders by Matsudaira Masatsuna, lord of Kawagoe Castle, who was responsible for the avenues along several of the Tokugawa highways. Tree-ring analysis of stumps from felled trees suggests the present population was actually planted around Manji 3 (1660), but the late-seventeenth-century date is broadly consistent.

The choice of cedar rather than the more usual pine reflects two things: the cool, damp climate of the lakeshore, where cedar thrives better than pine, and the road's relationship with the Hakone Gongen (now Hakone Shrine), whose precincts traditionally favoured the species. Several of the surviving trunks measure four metres in circumference. The oldest specimens approach 400 years.

This was not always so quiet a place. In 1904 (Meiji 37), to raise funds for building a new road from Yumoto to the lake, the authorities felled and sold more than a thousand pines and cedars along the old Tōkaidō. The avenue we see today is a remnant.

Walking the Old Road Today

The most popular route, and the one with the highest concentration of designated stone pavement, runs from Hakone-Yumoto station up to Moto-Hakone on Lake Ashi. The distance is about 11.5 km with around 680 metres of climb. Most walkers take four to five hours.

From Yumoto, the road passes the site of the 22nd milestone at Yumoto-chaya, climbs through the village of Hatajuku, and then enters the seven-switchback section that gave many an Edo traveller pause. Above the switchbacks the path winds past the Amazake Chaya, a thatch-roofed tea house run by the same family for twelve generations, where you can still drink the sweet, alcohol-free fermented-rice amazake that has been their speciality for around 350 years. Past the tea house the road descends through the Cedar Avenue to Moto-Hakone.

The western slope from Hakone Pass down to Mishima is longer, less wooded, and quieter. Walking it in full takes most of a day, but the section between Yamanaka Castle ruins and the Sasahara Ichirizuka is a reasonable half-day option that takes in most of the restored Mishima pavement.

The stones are slippery in rain and especially treacherous when descending. Sturdy walking shoes or light hiking boots are not optional. Several short sections were closed or rerouted after the 2019 Typhoon Hagibis (Reiwa 1 East Japan Typhoon), particularly on the Kannami Town side; check the latest local notices before setting out.

Around the Route

Hatajuku, halfway up the eastern slope, is the birthplace of Hakone yosegi-zaiku, the geometric wooden marquetry that has been a local craft since the early nineteenth century. Several workshops along the road sell finished pieces and run short courses.

At Moto-Hakone, the reconstructed Hakone Sekisho (checkpoint) stands at the lakeshore where it controlled traffic on the road from 1619 until 1869. The reconstruction, opened in 2007, was built using surviving Edo-period documents and is among the most thoroughly researched checkpoint reconstructions in Japan. The adjoining museum holds documents and travel implements from the Tokugawa traffic system.

The western terminus of the road is Mishima Taisha, the head shrine of the Mishima cult and an important devotional stop for travellers preparing to cross or descending from the pass. Its grounds hold a fragrant olive (kinmokusei) said to be over 1,200 years old and a National Natural Monument in its own right. The eastern terminus, Odawara, holds Hōjō-clan castle remains and a substantial Edo-period townscape along its own surviving stretch of Tōkaidō.