Suwa Onsen

The Limited Express from Matsumoto takes about 35 minutes along the Chuo Line before depositing you at Kami-Suwa Station, right at the edge of Lake Suwa. The lake is Nagano's largest, sitting at 759 meters above sea level in a flat basin between mountain ranges, and on a clear morning the water reflects the surrounding peaks so cleanly that you can barely tell where the surface ends. Walk ten minutes from the station toward the lake shore and you will start to see the thin plumes of steam rising from street vents and inn rooftops. The hot water is very close to the surface here. In fact, it sits so close that the Suwa Lake Geyser Center, right on the waterfront, sends it shooting five meters into the air on a regular schedule throughout the day.

The spring water at Kami-Suwa Onsen is classified as simple alkaline, registering at pH 9.7, which puts it firmly on the silky end of the spectrum. It emerges from the ground at 60 degrees Celsius, clear and odorless, without the sulfur edge you find at volcanic mountain springs further north. The water feels immediately smooth when you enter a bath, almost like it has a mild soap quality without any soap present. Your skin picks up a faint coating that stays for hours after you dry off, and in the cold dry air of a Nagano winter, that warmth retention is very noticeable. Local bathhouses around town, several of which are municipally operated and very inexpensive, use the water in both deep soaking tubs and shallow pools.

What grounds Suwa Onsen in something older than a resort is its proximity to Suwa Taisha, one of the most ancient shrine complexes in Japan. The four sub-shrines of Suwa Taisha, two on each side of the lake, predate written records and are connected to the surrounding landscape in a way that is not purely symbolic. At the Maemiya shrine on the western shore, the chozuya purification basin, where you wash your hands before entering, runs with actual hot spring water instead of the cold water you find at every other shrine in the country. It is an unusual thing to notice. You cup your hands under a stream that comes out warm and faintly slippery, and for a moment the division between the mountain water, the shrine, and the onsen collapses into something continuous.

Suwa itself is a working town with a precision manufacturing history, better known for optics and watchmaking than for hot spring tourism. The inns along the lake shore are solid and practical rather than extravagant, and the public footbath along the waterfront promenade is heavily used by locals on lunch breaks. The lake freezes in the coldest winters, and when it does, the ice makes a sound locals call Omiwatari, a deep crack and groan that crosses the surface in the early morning, which Shinto tradition interprets as the gods crossing the frozen lake between the upper and lower shrines. The timing of that crossing has been recorded without interruption for over 500 years.