De Wallen (Dutch pronunciation: [də ˈʋɑlə(n)]) or De Walletjes (Dutch pronunciation: [də ˈʋɑləcəs]) is the largest and best known red-light district in Amsterdam. It consists of a network of alleys containing approximately three hundred one-room cabins rented by prostitutes who offer their sexual services from behind a window or glass door, typically illuminated with red lights. Window prostitution is the most visible and typical kind of red-light district sex work in Amsterdam. De Wallen, together with the prostitution areas Singelgebied and Ruysdaelkade, form the Rosse Buurt (red-light areas) of Amsterdam. Of these De Wallen is the oldest and largest area. The prostitutes are a large tourist attraction. The area also has a number of sex shops, sex theatres, peep shows, a sex museum, a cannabis museum, and a number of coffee shops that sell marijuana.