men's bath; men's section in a public bath
Refers to the men's bathing area in a sentō (public bathhouse) or onsen (hot spring). Often contrasted with 女湯 (women's bath).
The men's bath is on the right, and the women's bath is on the left.
You can see the mountains from the men's bath at the hot spring.
Compound of 男 (おとこ, 'man') and 湯 (ゆ, 'hot water; bath').