The Hike, Onsen, Beer series revolves around the ideal trifecta: a challenging hike, a soothing soak in an onsen, and a well-deserved beer to cap off the day. The previous edition introduced the Kasama Alps in Ibaraki Prefecture, and this adventure similarly offers a rewarding escape just a short distance from Tokyo, beginning with a ride on the Atsu 20 bus from Hon-Atsugi Station to Miyagase (operated by Kanagawa Chūō Kōtsu) just before 9 AM. The Odakyu Line west of Machida is a popular route for weekend hikers, many of whom venture further toward Odawara to tackle Mt. Ōyama or Mt. Tō, or even a day trip to Mt. Tanzawa in the heart of the massif. Today, however, the bus took us 25 minutes north toward Lake Miyagase, skirting the edge of Tanzawa Quasi-National Park.
After getting off at the Susugaya bus stop, we consulted the Yama to Kōgen map for Tanzawa and followed signs pointing to Mt. Mitsumine. At 935 meters, Mitsumine may not boast towering heights, but its rugged terrain more than makes up for it. The trail begins at a deer gate, and shortly after, a sign informs hikers that the summit is 5 km ahead. The path quickly begins to ascend, offering occasional glimpses of the metropolis and Yokohama, and, on clear days, sweeping views of Sagami Bay and the Bōsō Peninsula
About halfway up, the trail splits. One option is a detour through Monomi Pass （物見峠）, but due to increasing erosion from heavy rains in recent years, it’s wiser to stick to the main ridgeline. The ridgeline itself is rugged and jagged, with narrow sections requiring some scrambling. Thankfully, strategically placed chains and ladders offer a welcome aid, and it took us just under 3.5 hours to reach the summit. Despite being under 1,000 meters, the hike is far from easy, with steep, eroded trails and exposed ridges making for a challenging ascent. Winter brings icy conditions, while summer brings leeches. The ideal time to visit is late autumn or early spring, and we made sure to arrive before the leeches made their appearance.
The small summit of Mt. Mitsumine offers seating, making it a pleasant spot for a lunch break. On a weekday, we encountered only a couple of other hikers heading in the opposite direction. From the summit, while it is possible to return the way you hiked, it is recommended to continue along the next section of the trail, following the jagged ridge toward Karasawa Pass (唐沢峠）. Some parts of the ridge are indicated by dashed lines on the Yama to Kōgen map, suggesting a more difficult path. However, pink tape marks the route, and with careful attention, staying on track is manageable.
At Karasawa Pass, instead of continuing toward Mt. Ōyama, we took the path leading down toward Fudojiri and Nanasawa Onsen. The trail zigzags down the mountainside through pleasant, mixed forested areas, eventually reaching a gravel road beside a brook. This road winds through woodland along the river, passing a farming community with citrus orchards and fish farms, leading into the Nanasawa and Kotakuji Onsen areas. Along the way, test your courage as you pass through the eerie, deserted Yamagami Tunnel. Soon after, you’ll reach a spring where visitors from far and wide come to collect the mineral-rich water flowing from the mountainside.
Soon, we arrive at Nanasawa-so. Located just an hour from central Tokyo in Atsugi City, this hot spring inn boasts an exceptional natural hot spring, renowned for its skin-beautifying properties. The name “Nanasawa” comes from its rich water sources, complemented by seven streams that meander through the area. The spring’s clear, colorless water provides a soothing, lotion-like sensation, earning it the nickname “lotion bath” for its rejuvenating effects and ability to keep the body warm after bathing. An outdoor sauna further enhances the experience. The inn also serves exquisite seasonal dishes, including wild boar hot pot, made with fresh, locally sourced ingredients, praised for their exceptional flavor and presentation. After soaking, we walked down to the main road and, from the “Kotakuji Onsen Iriguchi” bus stop, took a 20-minute bus ride back to Hon-Atsugi Station.
Refreshed from both the hike and the hot springs, we headed straight to the Sankt Gallen Brewery Taproom, just across from the station. This local Kanagawa brewery offers 20 varieties of their own draft beer, including Pale Ale, IPA, Weizen, fruit beers, and even barley wine, along with 12 types of pizza, 14 kinds of cheese, and 10 varieties of sausages. The generous servings of beer and the laid-back, welcoming atmosphere provide the perfect setting to relax and reflect on the day’s adventures. It stands in sharp contrast to the rugged ridgeline of Mt. Mitsumine and the tranquil onsen waters.
Mt. Mitsumine is not for the faint of heart, but with a map in hand and a fellow hiker to help navigate the more challenging stretches, it promises a rewarding and exhilarating experience. The trail is full of adventure, culminating in a peaceful onsen and, once back in Atsugi, an exceptional selection of beers to help you unwind. This holy trilogy of nature, relaxation, and indulgence is just a short journey from the vibrant pulse of the city, offering a taste of Japan’s finest outdoor pursuits within easy reach.
Places / Information
- Bus
Atsu 20 (Hon-Atsugi Station – Miyagase, Kanagawa Chūō Kōtsu) - Route
Susugaya bus stop ▶︎ Mitsumine trailhead ▶︎ Mitsumine summit (934.6m) ▶︎ Karasawa Tōge ▶︎ Fudojiri ▶︎ Kotakuji Onsen Iriguchi bus stop.
The hike takes 6+ hours; avoid wet or icy conditions and June–October due to leeches.
The route from Nanasawa to Atsugi Bus Center is served by the Atsu 33 bus. - Onsen
Nanasawaso https://www.nanasawasou.jp/
Address: 1830 Nanasawa, Atsugi, Kanagawa
Phone: 046-248-0236 - Beer
Sankt Gallen TAP ROOM https://www.sanktgallenbrewery.com/taproom/
Location: Outside the north exit of Hon-Atsugi Station, Kanagawa, Atsugi City, Nakacho 2-2-1
Phone: 050-5593-5087