Montevideo's largest downtown plaza commemorates independence hero José Artigas with a 17m, 30-ton statue and the subterranean Mausoleo de Artigas, where an honor guard keeps 24-hour vigil over Artigas’ remains. Other notable structures surrounding the plaza include the stone gateway Puerta de la Ciudadela, a lonely remnant of the colonial citadel demolished in 1833; the 19th-century Palacio Estévez; and the 26-story Palacio Salvo, the continent’s tallest building when it opened in 1927, and still a classic Montevideo landmark.