"Building with flashing signs outside"? In my experience brothels go out of their way not to draw attention to themselves! In the UK at least, a blatant brothel is a shut brothel.
It's very different in Spain where the "Clubs" do indeed advertise themselves with flashing neon signs visible for miles around.
Best club I visited was The Riviera , near Barcelona, Upwards of a hundred girls all sizes and shapes working there at any time , luxurious rooms with jacuzzis, frequented by affluent businessmen ,tourists , all sorts. There was no sense of shame or trying to hide what was going on. Valet parking for all the Mercs and BMWs , taxis lining up in the streets for punters exiting the Club.
Local police made sure there was no trouble but unfortunately it was closed down a few years ago because of trouble with some Romanian girls working there. Really miss that place , guaranteed a good night out.