A red-light district is a neighborhood where prostitution is a common part of everyday life. The term was first recorded in the United States around 1890, and derives from the practice of placing a red light in the window to indicate to customers the (often illegal) nature of the business. This is based on the biblical story of Rahab, a prostitute in Jericho who aided the spies of Joshua and identified her house with a scarlet rope.

Interestingly, one of the many terms used for a red-light district in Japanese is akasen (赤線), meaning "red-line district".

Famous red-light districts

Africa

• Wagh el Birket - Cairo, Egypt
• Avenue Lalla Yacout - Casablanca, Morocco
• Petit Socco - Tangier, Morocco

Asia-Pacific

• Patpong - Bangkok, Thailand
• Sukhumvit Road Area (including Nana Plaza and Soi Cowboy) - Bangkok, Thailand
• Pattaya, Thailand
• Dashilan - Beijing, China
• Wanchai - Hong Kong
• Hira Mandi - Lahore, Pakistan
• Kamathipura - Mumbai, India
• Svay Pak - Phnom Penh, Cambodia
• Geylang - Singapore
• Kings Cross - Sydney, Australia
• Kabukicho - Tokyo, Japan
• Yoshiwara - Tokyo, Japan (in Edo period)

Europe

• Rue d'Aerschot Brussels, Belgium
• De Wallen - Amsterdam, Netherlands
• Raval/Barri Xines - Barcelona, Spain
• Picin Park - Belgrade, Serbia
• Jozsef Utca - Budapest, Hungary
• Reeperbahn - Hamburg, Germany
• Intendente - Lisbon, Portugal
• Cais do Sodré - Lisbon, Portugal
• Kings Cross - London, England
• Piccadilly Circus - London, England (formerly)
• Soho - London, England
• Boulevard de Clichy - Paris, France
• Pigalle - Paris, France
• Union Street - Plymouth, England (formerly; now Millbay)
• Piazza Vittorio Emmanuele - Rome, Italy

North America

• The Block - Baltimore, Maryland
• Combat Zone - Boston, Massachusetts (formerly)
• Scollay Square - Boston, Massachusetts (razed)
• Venus Alley - Butte, Montana (formerly)
• The Levee - Chicago, Illinois
• Sunset Boulevard - Hollywood, California
• Hotel Street - Honolulu, Hawaii, Hawaii
• La Merced - Mexico City, Mexico
• Zona Rosa - Mexico City, Mexico
• Storyville - New Orleans, Louisiana (formerly)
• Times Square - New York City, New York (formerly)
• Marcy Street - Portsmouth, New Hampshire (1890s–1912)
• Sepulveda Boulevard - San Fernando Valley, California
• Barbary Coast - San Francisco, California (formerly)
• 14th Street - Washington, District Of Columbia (formerly)