Numajiri
Hot Spring Overview
The discovery of the Nakanosawa–Numajiri Onsen dates back approximately 380 years, to the Bunroku era (late 16th to early 17th century).
It began as a hot spring retreat for therapeutic bathing at the foot of Mount Adatara.
The source of the hot spring is Numajiri Motoyu, which flows from near the crater and valleys of Mount Adatara.
With a discharge rate of 13,400 liters per minute, it holds the record as the largest single hot spring source in Japan.
According to a 2009 survey by the Aizu Health Office, this impressive flow was officially confirmed.
The water is a well-balanced sulfur spring, rich in sodium, which helps warm the body, and metasilicic acid, known for its moisturizing properties.
Hot Spring Details
Practical Info
Visit Log
Bath Types
Facilities
Access Information
🚗 By Car
From the Adatara-yama Numajiri Trailhead Parking Lot, it takes approximately 45 to 60 minutes on foot to reach the hot spring.
Map
Loading map...
Click the marker to view detailed information
About Secluded Rating
Access (Difficulty to Reach)
Over 1 hour walk
Scenery & Atmosphere
Untouched nature
Onsen Value
Historic unique spring
Access is only possible on foot, and visitors can enjoy free-flowing hot spring water that flows directly into the Sulfur River.
However, hydrogen sulfide gas is present in the area, and there are restricted zones where entry is prohibited, so caution is required.
From the Adatara-yama Numajiri Trailhead Parking Lot, follow the mountain trail for about 45 to 60 minutes to reach the site.
Along the way, you can fully experience the natural beauty of Mount Adatara.