stone sauna; heated rock bath
A spa facility where one lies on towels placed on a heated slab of natural rock, similar to a sauna. Often contrasted with 岩盤浴, which may refer to the bathing style itself.
See also: 岩盤浴
This hot spring has a stone sauna.
I sweated in the heated rock bath.
岩盤浴 often refers to the practice or style of lying on heated rocks, while 岩盤風呂 emphasizes the facility or bath itself.
Compound of 岩盤 (rock bed) and 風呂 (bath).