Walk out of the grand entrance of the Westin Paris and turn left. The road you're on is the Rue De Castiglione. Three blocks down, turn right (you will see the entrance of the Metro - don't remember the name). Directly diagonal from that entrance, you will see it. Don't remember its name either (I don't speak French). Clientele is largely male, of course. If you're going at night, there's the redlight at the door, so you definitely won't miss it.