Mount Ena is a 2,191-meter-high mountain straddling Achi Village in Nagano Prefecture and Nakatsugawa City in Gifu Prefecture. It lies at the southernmost end of the Kiso Mountains, also known as the Central Alps. The mountain has been selected as one of Japan’s 100 Famous Mountains and the New 100 Famous Flower Mountains. It is also part of the Hozan Prefectural Natural Park designated by Gifu Prefecture.
Rising majestically above the city of Nakatsugawa, Mount Ena has a broad, distinctive silhouette resembling a large comb. Its imposing profile can be seen from the Nobi and Okazaki plains, and even from the distant Ise Plain.
The highest point of Mount Ena stands at an elevation of 2,191 meters. To its southeast are a first-order triangulation point, an observation platform, and the main inner sanctuary of Ena Shrine, located near the summit.
The observation platform is surrounded by tall coniferous trees, including Japanese spruce and Maries’ fir, so the views from there are relatively limited. However, near the junction where the trail from Kuroisawa, a tributary of the Nakatsu River, meets the main ridgeline, there is a mountain shelter known as the Mount Ena Summit Emergency Hut.
From the rocky area behind the hut, hikers can enjoy magnificent views of the Northern Alps, Mount Ontake, the Central Alps, the Southern Alps, and Mount Fuji.
Fujimidai Highlands lies northeast of Mount Ena, with the Ena-san Tunnel on the Chuo Expressway running directly beneath it.
At the northern foot of the mountain are Magome-juku and Tsumago-juku, historic post towns along the Nakasendo, one of the major roads connecting Edo, present-day Tokyo, with Kyoto during the Edo period.
Mount Ena was a familiar sight during the childhood of Toson Shimazaki, a celebrated Japanese novelist who was born and raised in Magome. The mountain also appears in his novel Before the Dawn. It is additionally depicted in A Letter in a Cement Barrel by Yoshiki Hayama, a writer associated with proletarian literature.
Mount Ena was once called Enasan, written with characters meaning “afterbirth mountain.” It was also known as Funafuseyama, a name referring to its resemblance to an overturned boat.
According to the historical account Yoshiryaku by Matsudaira Kunzan, the sun goddess Amaterasu is said to have been born on this mountain, and her afterbirth, known in Japanese as ena, was buried there. This legend is believed to be the origin of the mountain’s name.
On the Shinshu side, in Nagano Prefecture, the mountain was also known as Nogumayama.
Mount Ena supports a wide range of vegetation, extending from lowland hill zones to subalpine environments. The upper slopes are covered with coniferous forests containing species such as Momi fir, Maries’ fir, and Japanese spruce.
Until the early Edo period, the mountain’s western slopes were known for their beautiful forests of Japanese cypress and fir. However, excessive logging later caused considerable damage to these forests.
Hikers may encounter a variety of seasonal flowers along the trails, including Iwauchiwa (a spring-blooming woodland plant), Enkianthus flowers, rhododendrons, Shōjō-bakama, Zudayakushu, and Baika-ōren.
On May 11, 1893, British mountaineer Walter Weston made the first recorded ascent of Mount Ena via the Maemiya route.
In 1932, a major landslide disaster occurred in the foothills, causing extensive damage. In 1951, the mountain was included in Nagano Prefecture’s Central Alps Prefectural Natural Park. Kyūya Fukada, author of 100 Famous Mountains of Japan, climbed Mount Ena in 1960.
The Ena-san Tunnel on the Chuo Expressway opened in 1975, and Ena-san Weston Park was developed in 2001 to commemorate Walter Weston’s mountaineering achievements.
Mount Ena has long been revered as a sacred mountain. According to local tradition, the deities Izanagi and Izanami gave birth to Amaterasu in the ancient province of Mino and placed her afterbirth on the mountain.
Ena Shrine has an inner sanctuary near the summit and a main shrine at the foot of the mountain, known as the Maemiya. During the middle of the Edo period, practitioners of Shugendo, a Japanese mountain ascetic tradition, visited the mountain to worship.
The mountain continues to attract hikers and worshippers today, preserving its long-standing spiritual significance.
An annual mountain-opening festival is held at Fujimidai Highlands around April 29, marking the beginning of the climbing season. Ena-san Weston Park commemorates Walter Weston’s historic ascent in 1893.
There are several hiking routes on Mount Ena, including the Kuroisawa Route, the Misaka Pass Route, the Hirogawara Route, and the Maemiya Route. Observation points and emergency shelters are provided along the various trails.
Depending on the route and weather conditions, hikers can enjoy beautiful mountain scenery, including views of the Central Alps, the Southern Alps, and Mount Fuji. Mount Ena combines spectacular natural landscapes with rich botanical diversity, literary connections, and a long history of mountain worship.