A red-light district or pleasure district is a part of an urban area where a concentration of prostitution and sex-oriented businesses, such as sex shops, strip clubs, and adult theaters, are found. In most cases, red-light districts are particularly associated with female street prostitution, though in some cities, these areas may coincide with spaces of male prostitution and gay venues. Areas in many big cities around the world have acquired an international reputation as red-light districts.
The term red-light district originates from the red lights that were used as signs for brothels. Some red-light districts (such as De Wallen, Netherlands, or Reeperbahn, Germany) are places which are officially designated by authorities for legal and regulated prostitution.