Cedar Trees in Annakahara City

A Living Relic of the Nakasendō Highway

The Nakasendō was one of the five great highways (gokaidō) developed by the Tokugawa shogunate to link Edo (modern Tokyo) with Kyoto. Whereas the Tōkaidō hugged the Pacific coast, the Nakasendō wound through the mountainous interior, passing through sixty-nine post towns along its roughly 530-kilometre course. Within the Jōshū region (present-day Gunma Prefecture), seven post towns—Shinmachi, Kuragano, Takasaki, Itahana, Annaka, Matsuida, and Sakamoto—served as essential way stations for daimyō processions, government couriers, and ordinary travellers alike.

To shelter wayfarers from sun, rain, and snow, the shogunate ordered cedar (sugi, Cryptomeria japonica) and pine plantings along certain stretches of the great highways. The Haraichi cedars were among these. While the most famous surviving example of an Edo-period roadside planting is the Nikkō Sugi Namiki Kaidō, the Annaka–Haraichi avenue ranked alongside it as one of the most outstanding cedar-lined sections of any of the gokaidō.

When Were the Cedars Planted?

The precise origin of the avenue is the subject of three competing local traditions. The first attributes the planting to the early Tokugawa period, around the year 1604 (Keichō 9), when the new shogunate was rapidly developing the Nakasendō infrastructure. A second theory places the date slightly later, around 1615 (Genna 1). A third tradition credits Itakura Shigekata, a lord of the Annaka Domain, with ordering the planting. Whichever version is closest to the truth, all three point to a planting that took place in the seventeenth century, when Japan was being knitted together by an unprecedented network of carefully managed highways.

What is documented with certainty is the avenue's gradual diminishment. A survey from 1844 (Tenpō 15) recorded 732 cedars along the stretch. By 1932 (Shōwa 7), the year before national designation, only 321 remained. In 1967 (Shōwa 42), the Annaka section was removed from the designation because too many trees had died, leaving the Haraichi section as the sole protected portion. Today only about a dozen of the original giants survive—each one all the more precious for its rarity.

Why This Avenue Was Designated a National Natural Monument

The Annaka Haraichi Cedar Avenue was designated a National Natural Monument (Tennen Kinenbutsu) on 13 April 1933 under the framework of the Historic Sites, Places of Scenic Beauty, and Natural Monuments Preservation Law. Two principal reasons underpinned its protection.

The first was botanical magnitude. At the time of designation, the avenue stretched for over one kilometre and contained 321 trees, the largest of which had a girth (measured at chest height) of approximately five to six metres. In an age before motor vehicles disturbed roots and exhaust fumes weakened canopies, these cedars represented one of the finest surviving examples of a continuous wayside cedar plantation in the country.

The second reason was cultural and historical. The avenue was a direct material witness to the Edo-period highway system. Walking beneath its boughs, one could still feel the rhythm of pre-modern travel—a quality the Agency for Cultural Affairs sought to preserve for future generations. Although the avenue has shrunk dramatically since 1933, this very fragility makes the surviving trees an object lesson in heritage stewardship.

Highlights and What to Look For

Today the surviving cedars cluster in a short, evocative stretch along the prefectural road that follows the line of the old Nakasendō. While the avenue no longer forms an unbroken green tunnel, several features reward unhurried observation.

The first is sheer scale. The largest survivors retain trunks of remarkable thickness—reminders that Japanese cedars can live for many centuries and reach truly imposing dimensions. Standing close to one of the old giants and looking upward gives an immediate, physical sense of how the avenue must once have appeared to a weary Edo-period traveller.

The second is the avenue's place in regional memory. In Gunma Prefecture, almost every child grows up reciting the Jōmō Karuta, a traditional card game of local lore. The card for the syllable "na" reads "Nakasendō, shinobu Annaka sugi-namiki"—"the Annaka cedar avenue evokes memories of the Nakasendō." For local residents, these trees are not simply old plants but a familiar verse made tangible.

A third pleasure is the contrast with the surrounding countryside. The road winds through fields and quiet residential lanes, and the cedars rise abruptly from this gentle landscape, marking the path of the old highway as clearly as any signpost.

Surrounding Attractions

The cedar avenue makes an excellent anchor for a half-day or full-day exploration of Annaka's Nakasendō heritage. Within a short drive lies the old Annaka-juku district, where reconstructed samurai longhouses and the former Usui County Office offer a sense of the post town's Edo- and Meiji-era civic life. The Niijima Jō Memorial House preserves the family home of Niijima Jō (Joseph Hardy Neesima), founder of Doshisha University, who was born into the Annaka domain's samurai class.

Further west along the old highway lies the dramatic Usui Pass, the most demanding section of the Nakasendō between Edo and Kyoto. The Usuitōge Railway Cultural Village commemorates the abandoned Abt-system railway that once climbed this pass, and a walking trail known as the Apt no Michi leads past several Important Cultural Properties of industrial heritage, including the elegant brick Megane-bashi (Usui Daisan Bridge). The hot-spring town of Isobe Onsen, the Myōgi mountain range, and the famous Tōge no Kamameshi boxed lunch served at Yokokawa Station are all easily accessible day-trip destinations.

Visitor Information

The cedar avenue is a roadside heritage site rather than a managed visitor attraction. There is no entrance fee, no opening hours, and no ticket office. The trees can be observed from the prefectural road that follows the line of the old Nakasendō through the Ichirizan area of Haraichi. Visitors are asked to remain on the road or the verge and to refrain from touching, marking, or climbing the trees; the surviving giants are old and ecologically fragile.

Public transport is limited. The most practical approach is by car from the Matsuida-Myōgi or Annaka-Haruna interchanges of the Jōshin-Etsu Expressway, or by rented bicycle from JR Annaka or Annaka-Haruna stations. Spring and autumn offer the most comfortable walking conditions; winter air is clear but cold, while summer brings the dense green canopy at its fullest.