CUBA, formerly known as Black, is a gay 'jjimjilbang' (cruise club) that made headlines in 2015 for admitting to having a strict door policy that allowed entry only to young Koreans and gym-fit non-Korean men.
Facilities at Black include lockers with keypad system, showers, bathrooms, TV/smoking room, private cabins and dark room. Black gets very crowded and particularly busy on the weekends. Open 24 hours.
From Sinnonhyeon subway station (Exit 3), take the first turn on the left down Gangnam-daero 112-gil. Continue down this street until you find an alley on the left.