The stories about the Barcelona saunas are mixed. At least the guys are very hot! Some saunas are frequented by rentboys.

Gay cruise bars and clubs

Berlin Dark
Passatge de Prunera 18
Berlin Dark is a gay cruise club for lovers of naturism, fight and contact sports, leather, rubber and other fetish and S&M practices. [...]
tue-sun 22:30–02:00
Carrer de Calàbria, 96
BoyBerry is a new concept of leisure, a multiconcept shop, cruise club. A videoclub with the biggest amount of gay themed movies, at the best prices. [...]
mon-fri 12:00–23:00, sat-sun 15:00–00:00
New Chaps
Avinguda Diagonal, 365
One of the most frequented leather bars in town, but not many men in real leather or anything. [...]
mon-sat 21:00–03:00, sun 19:00–03:00
Open Mind
Aragon Nº 130, Universitat
Great location is you like gay fetish and cruising. Open Mind is by far the best in Barcelona in its kind. [...]
wed-thu 23:00–04:00, fri-sat 23:00–07:00, sun 19:00–04:00