Most people who are outdoor enthusiasts in Japan love hopping into onsen. Some are clear, others milky white or dark and muddy. There is fresh, sweet water and the sulfurous belchings of the pit. Regardless, hot springs in Japan are the perfect reward after a hard-earned snowboard, ski, hike, trail run, climb, cycle or just a hard week at the office.
Public onsen and hot spring hotels are found throughout Japan. Yet some would argue the purest onsen experience is going to the source (of the hot water), shovel in hand to dig river sand, haul rocks and arrange them to create your own natural pool for a soak.
Nagano’s Yumata Onsen is a stunning spot to do just that. It is located in an area owned by the Tokyo Electric Company and, from the Nanakura Dam parking area, you must take a taxi up through dam tunnels and access roads until you reach Takase Dam. This is the biggest natural rock fill front of any dam in Japan and is the second highest (after Kurobe). It is possible to walk the five-kilometer journey, but be sure to factor in the extra time to avoid any stumbling around in the dark.
Setting off along the left side of the Takase Dam, it is a gentle walk along seldom-used access roads for the first hour, with the lake on your right and the soaring mountains of the Japan Alps all around. Dead trees still poke up out of the lake as ghostly remnants of when the valley was flooded.
You’ll pass through three tunnels, one of which is nearly a kilometer long and dead straight with only a tiny spot of daylight at the other end. Have fun clapping and playing with the echoes until you emerge. As you walk along the lake away from the dam, the rocky banks and riverbed become more expansive, and you can begin to envisage the vast volumes of snowmelt that must pound down here in spring, tossing and scrubbing these huge boulders.
Once past the tunnels, keep your eyes and ears open, as there is plenty of wildlife, such as kamoshika (Japanese serow), which quietly watch you from the undergrowth, and troops of wild monkeys. After an hour or so, the access road disappears and the path continues to wind along the edge of the river, in and out of shady forest sections and sandy river beaches with plenty of great spots to enjoy some tea and take in the alpine scenery.
Coming around a left-hand bend in the river, approximately two and a half hours after leaving the dam, you’ll see the Seiransou Lodge ahead on the other side of a wire bridge. You will receive a friendly reception and are free to pitch your tent where you choose for ¥500 a night.
Food is usually available to campers but best to call ahead to confirm if you are not carrying any. If you’re lucky, you may even be invited to try kotsusake - fresh iwana (char) lightly stewed in sake.
Guidebooks will show pictures of folks serenely enjoying the hot pools directly in front of the lodge at Yumata Onsen, but nature, being all about change, may have other plans. Do not be surprised to find the pools no longer there. Recently, after a flood, the hot spring directly in front of the lodge simply stopped flowing. If this happens, the indoor bath is available but, with a bit of daylight left, it is best to go in search of your own.
The relatively easy hike should leave you with more than enough energy for digging, and digging is the real reason to come to Yumata. The lodge is happy to help by keeping a supply of picks and shovels you can borrow as you head out in search of your own rotenburo (outdoor bath).
From the lodge, go up the main Takase River and past the small shrine for 15 minutes or so, and you will notice the water starts to become a stunning clear greenish-blue while the rocks near the water become whitish-yellow due to the sulfur. From here, there is (very) hot water springing up all along the edge of the river, and you may find some nice pools waiting for you.
Be sure to venture a little further up the river as well, on the other side you will find a steaming two meter-high mound of sulfur crystal deposited by the largest spring in the area. If the elements have not left you a ready-made pool, scout around to find some remnants and make your own. Dig out the sand and place rocks, and then adjust the mix of hot onsen water and river-water to your liking.
There are no guarantees you’ll get the perfect bath, such as at a fancy onsen ryokan, but with a little luck, you will get a quintessential Japanese experience - a slight adjustment to your natural surroundings to create a sublime, relaxing commune with nature with soaring mountains and steep rock faces all around.
Seiransou Lodge (晴嵐荘)
Seiransou Lodge is open from July to the middle of October. The closing date is not fixed, so please call first to check. Walk time from Takase Dam is two and a half to three hours. The toilet at Takase Dam is the last one until you reach the lodge. One night with two meals is ¥8,500. Tel: (0261) 22-0165. Camping is ¥500 a night. The bath in the lodge is ¥500 for campers and may not be available during the daytime.
Getting There By Train: From Shinjuku take the Super Azusa to Matsumoto, then take the Oito Line to Shinano-Ōmachi Station. From there, taxi to Takase Dam (45 minutes).
By Car: Take the Chuo Expressway to Okaya Junction, then the Nagano Expressway toward Nagano. Exit at Toyoshina I.C., then follow Route 147 to Route 326 to Nanakura Dam. From Nanakura Dam Parking Area, take a taxi to Takase Dam.
Useful Info: Seiransou Lodge can also be used as a base camp to climb the north side of Yarigatake and Noguchigoroudake. Take towels, even if you plan to stay in the lodge. Take care, as the water can be scalding hot. Caution is especially recommended if you try to cross the river and also near the sulfur pillar and steam. The walk is not very demanding, but reasonably sturdy shoes are recommended for clambering around on rocks near the water. Early autumn can be quite cold at night and, in the early morning, if you’re camping, be prepared.