De Wallen, also known as Walletjes or Rosse Buurt, is the largest and best-known red-light district in Amsterdam, a major tourist attraction. It is a network of alleys containing several hundred tiny one-room apartments rented by female prostitutes (and some ladyboys) who offer their services from behind a window. It also has a number of sex shops, sex theatres, peep shows, a sex museum, a cannabis museum, and a number of coffee shops offering various cannabis products.

De Wallen is located in the heart of the oldest part of Amsterdam, covering several blocks south of the church Oude Kerk and crossed by several canals. The name Wallen refers to the names of the two canals in the area, the Oudezijds Achterburgwal and the Oudezijds Voorburgwal. The red light district has existed since the 14th century and formerly contained many distilleries, mainly catering to sailors.

Prostitution is generally legal in the Netherlands, however some of the working women are illegal immigrants. Health and social services are readily available, but the women are not required to undergo regular health checks. A recent study found that about 7 percent of all Dutch prostitutes (including street prostitutes) have HIV/AIDS.

The women in De Wallen are self-employed and rent the rooms from private owners for some 100-150 euros per 8 hour shift, which includes closed-circuit security. Condoms are generally used for sexual contact, although not always with oral sex. Twenty minutes of sex typically costs about 40 to 50 euros, sometimes with a 20 euro surcharge for the girl to take off her top. There are women of most nationalities offering services.