upper hot spring pool; upper bath
Refers to a higher-elevation bathing area in a hot spring facility; mainly used in proper names such as 上湯温泉.
Kamiyu Onsen is located higher up the mountain.
The inn has two baths: an upper bath and a lower bath.
Compound of 上 (かみ, 'upper') and 湯 (ゆ, 'hot water'). The reading かみゆ follows standard rendaku avoidance.