The Secretariat of the International Bureau of Weights and Measures ("Bureau international des poids et mesures" or BIPM) is based at Saint-Cloud, France. It has custody of the now historical international prototype of the kilogram and provides metrology services for the CGPM and CIPM, and hosts their formal meetings. It also has custody of the former international prototype of the metre which was retired in 1960. Over the years the various prototypes of the metre and of the kilogram were returned to BIPM headquarters for recalibration services.