the men's bath!?Ehh...you mean this place is... Mount Osore onsen: Yakushi no Yu 恐山温泉薬師の湯 is a hot spring located in the vicinity of Mount Osore in Aomori Prefecture, Japan. It is a part of the Osorezan temple complex and is known for its free-flowing sulfuric acid hot spring. The hot spring is called “薬師の湯” (Yakushi no Yu) in Japanese. It is a simple and rustic facility with separate bathing areas for men and women.