Camille Flammarion's observatory, located in Juvisy-sur-Orge in the suburbs of Paris, has been idle since 1962. Property of the Société Astronomique de France (SAF), it was made available to the city of Juvisy-sur-Orge since 1971, and contains a unique collection of objects and books currently being sorted out. The observatory is being restored by the SAF, thanks to the support of the city of Juvisy-sur-Orge, the French Académie des Sciences and the “Amis de Camille Flammarion” association. In 2006, the Maxime Goury Laffont foundation funded the refurbishment of the 240 mm refractor and in 2007 funds were obtained to restore the dome and central building. The main aim of the project is to make this historical place a popular observatory dedicated to astronomy and the sciences which Camille Flammarion enjoyed and contributed to. It constitutes a unique example in France of synergies linking associations, municipality, regional- and national-level institutions.