Gatchina (gäˈchēnə) [key], city (1989 pop. 80,000), NW European Russia. The city developed around the imperial palace (built 1766–81), which was used as a summer residence by Paul I in the 18th cent. and was a favorite residence of the Russian czars. The palace (now a museum) was looted and damaged by the Germans in World War II and has been partly restored. The Petersburg Nuclear Physics Institute is in Gatchina.