Cayenneis thecapital cityofFrench Guiana, anoverseas regionanddepartmentofFrancelocated inSouth America. The city stands on a former island at the mouth of theCayenne Riveron theAtlanticcoast. The city's motto is "fert aurum industria" which means "work brings wealth".Tropical-colored Creole-style houses sit beside hilltop ruins of the French colonial Fort Cépérou, which overlooks the Cayenne River.