The Pavillon de l'Arsenal is the Paris Center for architecture and urbanism, a center for urban planning and museum located in the 4th arrondissement at 21, boulevard Morland, Paris, France. It is open daily except Mondays; admission is free. The museum building was built in 1878-1879 for Laurent-Louis Borniche, wood merchant and amateur painter, near the former site of a Celestine monastic community turned arsenal. In 1988 it became a center for documentation and exhibitions related to urban planning and the architecture of Paris.