Onsen OniOnsen Oni

Tsubo-yu

湯の峰温泉 つぼ湯ゆのみねおんせん つぼゆ

Foot Bath
Kumanohongu Onsen-goYunomine Onsen
Kansai·Wakayama
0735-42-0074hongu.jp

つぼ湯

Tsubo-yu

Operated by · 田辺市四村川財産区

Sampled at wellhead
黄
Sulfur
+ Bicarbonate · Chloride
Classification

Sodium Bicarbonate-Chloride spring

Named simply after the cave-bath itself, Tsubo-yu is a sulfur-bearing sodium bicarbonate-chloride spring — the soft, skin-smoothing 'jūsō-sen' bicarbonate frame layered with a salty, heat-retaining chloride finish, all carried on a quiet H₂S note. At pH 6.9 it sits in neutral territory; the water emerges colourless with a faint rotten-egg whisper and a mild sulfur taste on the lips. Metasilicic acid is generous at 95.5 mg/kg, leaving the kind of fine silica film that makes skin feel noticeably smoother afterwards. The source rises naturally at 53.5 °C and feeds the small rock-pool tub that gives the spring its name along the Kumano Kodō pilgrim route.

pH
6.90
Neutral
Source temperature
53.5°C
Hot
Tonicity
1.67g/kg
Hypotonic
Free CO₂
72mg/kg
Low
Free H₂S
0.70mg/kg
Low
Color
colorless and transparent
Taste
weakly sulfur
Odor
weak hydrogen sulfide
Highlights
  • High silica

Analyzed Mar 20, 2015·一般社団法人 和歌山県薬剤師会 医薬品・公衆衛生検査センター·Cert no. G1502080号

Highlights

Foot Bath

Loading map…

SM
Sergey M
10 months ago

608. Tsubo-yu, Yunomine Onsen, Wakayama ★★★ A UNESCO onsen in kashikiri format. 800 yen for 30 minutes. Operating hours stated as 06:00 to 21:00. No reservations - first come, first served. You need to buy a ticket at the vending machine of the public onsen Yunomine Onsen Koshuyokujo and get a queue number at the counter. I arrived by bus at the 6 AM opening and got queue ticket number 4. After getting your number, walk along the river to the gazebo near Tsubo-yu. If the chain before the stairs down is closed, the bath is occupied and you have to wait. From the bridge you can see the entrance door and check which queue number is currently using the onsen (the number tag is hung by the door) - that's how you track the queue. Before entering, hang your number tag by the door and take off your shoes; after leaving, take the tag back to the public onsen counter. Inside - an old-school onsen. The atmosphere is gorgeous, plus there's a loud pleasant sound of water from the river. The water is milky blue-white with a slight smell, temperature was 46.7. There are cold water taps. The air inside feels good. Top-tier spot, essentially a must-visit when in Kawayu or Yunomine Onsen. 14.06.2025