Erected on the site of a royal gunpowder factory in 1878–79 by the architect Clément, the Pavillon de l’Arsenal was acquired by the city of Paris in 1954 to house building archives. In?1988, it was reopened as a public exhibition space, after being refurbished by the architects Bernard Reichen and Philippe Robert. Today, it houses archives and a documentation of the urban and architectural development of the city. (Uli Seher)