The Panama Canal Zone (Spanish: Zona del Canal de Panamá), also simply known as the Canal Zone, was an unincorporated territory of the United States, located in the Isthmus of Panama, that existed from 1903 to 1979. It was located within the territory of Panama, consisting of the Panama Canal and an area generally extending five miles (8 km) on each side of the centerline, but excluding Panama City and Colón. Its capital was Balboa.