Yunokuchi Onsen

Yunokuchi Onsen is a secluded hot spring nestled deep in the mountains along the Kitayama River in Kiwa-cho, Kumano City, Mie Prefecture. Its origins date back approximately 700 years to the Nanbokucho period, when the spring was reportedly discovered during gold mining operations ordered by Emperor Go-Daigo. Designated as a National Health Resort Hot Spring by Japan's Ministry of the Environment, it is known as a tranquil therapeutic bathing destination surrounded by the lush nature of Oku-Kumano. The spring dried up in the early Showa era due to mining activity but was revived in 1979 after a boring survey following the mine's closure in 1978 rediscovered the source at a depth of 1,300 meters underground.

The water is classified as sodium-calcium chloride spring (hypotonic, mildly alkaline, high temperature) with a source temperature of 44.7 degrees Celsius and an abundant flow rate of 1,120 liters per minute. The facility maintains a completely free-flowing source water system with absolutely no dilution or artificial heating, and all baths are drained and thoroughly cleaned daily. The spring is known for its therapeutic benefits for neuralgia, muscle pain, joint pain, cold sensitivity, and fatigue recovery.

Renovated and reopened in 2015, the bathing facility makes generous use of Kumano cedar, creating a warm and aromatic atmosphere. It features indoor baths, outdoor baths, standing baths, lying baths, half-body baths, and private rental baths. The forest-surrounded outdoor bath offers immersion in nature across all four seasons. Accommodation options include bungalows, lodges, and cottages suitable for extended therapeutic stays. The facility is connected to Iruka Onsen Hotel Seiryuso by a unique trolley train running through an abandoned mine shaft, offering a memorable 10-minute ride.