Kishu Shirahamaonsen Musashi

紀州・白浜温泉むさし

Lodging
Kansai·Wakayama

Day Use

Yes

Bathing & Water

Outdoor BathYes

Open-air outdoor bath

Indoor BathYes

Enclosed indoor bathing area

SaunaYes

Dry heat sauna room

Cold BathYes

Cold water plunge bath, typically used after sauna

OnsenYes

Uses natural hot spring water

生明湯

Ikumei-yu Spring

Operated by · 白濱温泉土地株式会社

Sampled at wellhead
Chloride
Classification

Sodium Chloride spring

A sodium chloride spring of hypertonic, near-neutral character that emerges at 66.8 °C — among Japan's hotter natural sources. Mineralization of 18,180 mg/kg gives it a pronounced salty body that leaves a mineral film on the skin. A respectable 106 mg/kg of metasilicic acid layers in a touch of silica smoothness on top of the salt.

pH
7.00
Neutral
Source temperature
66.8°C
Hot
Tonicity
18.18g/kg
Hypertonic
Flow rate
171L/min
Typical
Free CO₂
132mg/kg
Low
Color
colorless and clear
Taste
bitter with a strong salty edge
Odor
odorless
Highlights
  • Top-decile hot
  • High silica

Analyzed Nov 14, 2013·和歌山県環境衛生研究センター·Cert no. 温泉第1035号

Programs

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SM
Sergey M
3 months ago

688. Kishu Shirahamaonsen Musashi, Shirahama, Wakayama ★ Visited in the evening for higaeri on the tegate pass. Higaeri hours are 15:00-22:00 (except Golden Week, July, August, New Year's). Included in the Shirahama tegate (2 stickers). They sell the Wakayama 12 Onsen stamp book. The ryokan's website also shows another bath described as an infinity bath upstairs, but based on the description it seems available only to certain guests. 1. Outdoor stone bath, no view. Clear water, temperature around 42.5. 2. Indoor area on the second floor. Very large space. Breathing inside is comfortable. 2.1. Large bath with clear water, temperature around 42.5. 2.2. Small bubble bath, clear water, temperature around 40. 3. Indoor area on the first floor. Breathing inside is comfortable. Photos of the bath from the internet match. 3.1. Bath with clear water, temperature around 41.5. 3.2. Sauna. 3.3. Cold bath. Pleasant place with solid onsen offerings - worth keeping in mind when visiting Shirahama. 10.11.2025