noun
radium hot spring; radioactive hot spring
A hot spring whose water contains radium or other naturally occurring radioactive elements, often promoted for health benefits.
この地域にはラジウム温泉がいくつかあります。
There are several radium hot springs in this area.
温泉 is the general term for hot spring; ラジウム温泉 specifies the type of hot spring based on its mineral content.
Compound of ラジウム (radium) and 温泉 (hot spring). The term refers to hot springs containing radium, a naturally occurring radioactive element.