During my taipei trip a few weeks back, i went to this health plaza call Tian Long Sauna. It's more like Gspa style spa, many uncles and middle aged guys.. but got a few young guys also (saw a group of young koreans and japanese). The wet area is all nude so can see everything. The place is old but very well kept clean and tidy. They have big resting lounge area with one area there is a movie playing straight porn hahah.. went there twice during my taipei visit, since also during that time it was mostly raining becuase of the typhoon.