What is the significance of sex work for the architecture of the city? With reports from Amsterdam, Antwerp, Hong Kong, Montreal, and Taipei, this book makes clear that every red light district is the specific outcome of the morphology of the city, the legal status of sex work, cultural understandings, city planning, and market forces. It also shows that sex work has a deep impact on the city's urban form, its buildings, rooms, streets, squares, and alleys, even in places where sex work is officially illegal.