Boulogne92 may be right, but he is from the area. I personally never went there at night, and careless about it. Feel like a perve get sucked in the wood, by the way make sure is a girl, are there any drag left? And how you fuck a whore in the wood @#$%???
In year 2000, when I come back to Paris, friends told me whores were everywhere. Now the gov chased them away, and rightly so.
Otherwise I think Paris has really none, except now there are some new sex clubs opening with new services near Les Halles. Friends told me one can get laid inside, but who knows.
the best advise: ALWAYS ASK THE PRICE, and never go to pigalle, except to see moulin rouge.