Kamanuma Onsen Daikisen is a small secluded inn limited to 7 rooms per day, located along the Irikawa River, a tributary of the Otaki River, in Mitake, Kiso Town, Kiso District, Nagano Prefecture. As a member of the Japan Secret Hot Springs Preservation Association, it carefully maintains traditional therapeutic bathing culture. Renovated and reopened in March 2024, it adds new charm while preserving its traditional atmosphere.

The hot spring is a carbon dioxide-calcium-magnesium-bicarbonate cold mineral spring (hypotonic, weakly acidic cold mineral spring) with pH 6.12 and a source temperature of 11.1°C. The bathing area features two types of baths: a small source bath filled directly with the approximately 13°C spring water, and a larger heated bath. Guests can enjoy "alternating baths" between these two baths, which is said to be effective for promoting blood circulation and regulating the autonomic nervous system. While the cold source bath requires courage, those who try it often find it addictive.

The spring quality contains abundant carbonic acid and is known as a "skin-beautifying hot spring" with high skin-beautifying effects. After bathing, skin feels moisturized and a warming sensation persists deep in the body. Day-use bathing is available for 800 yen for adults (900 yen on weekends), 600 yen for elementary students (700 yen on weekends), operating from 13:00-16:00 (last entry 15:30). However, it's closed on Tuesdays and Wednesdays, and during winter (January-late March), it operates only on Fridays, Saturdays, and Sundays.

Accommodation is available in all 7 rooms, with rates from 13,000-39,000 yen per night with two meals, from 7,000 yen for room only, and from 9,000 yen with breakfast included. Meals feature medicinal kaiseki cuisine using local Kiso ingredients, offering gentle and deeply flavorful dishes. A free shuttle service is available from JR Chuo Line Kiso-Fukushima Station (one trip per day, departing at 15:30 for arrival, 10:00 for return), and it's about 15 minutes by car from the station. Free parking is also available. It's a hidden gem hot spring in Kiso where you can spend leisurely time listening to the murmuring of the river.