Top 10 red-light districts in the world

 Bahnhofsviertel, Frankfurt, Germany

Known as Bahnhofsviertel, the red-light district in Frankfurt is the biggest competitor of the one in Hamburg. Here you will find a number of strip clubs, sex shops and chat-up bars where women talk to you whilst sipping on the expensive drink you bought for her. There are also some Eros Centers, or licensed brothels, sprinkled across the area. These are all four-or-five-floor buildings with single rooms rented by prostitutes for the day or just a few hours. A closed door means that the lady is busy; an open door means that you can go in and negotiate a price.