Castro is a Chilean commune in the province of Chiloé, in Los Lagos Region X, in the Archipelago of Chiloé. Integra Precinct No. 58 and belongs to the 17th Senatorial District. Its capital is the city of the same name, located about 1214 km from Santiago, which is the third oldest city in continued existence of Chile, founded in February 1567, by Marshal Martin Ruiz de Gamboa. The communal area is 473 km ² and the total population, according to preliminary results of the census conducted in 2012, was 43,306 inhabitants, of which about 75% lived in the city of Castro.