酸ヶ湯Sukayu Onsen

Sukayu Onsen (酸ヶ湯, Sukayu) is an onsen (hot spring) in the city of Aomori, Aomori Prefecture. It is known for its "Sen-nin-buro" or "1,000-person bath", a large mixed gender public bath.

from Sukayu_Onsen (Wikipedia) CC BY SA 3.0