Cabildo is a Chilean city and commune located in the Petorca Province, Valparaíso Region. The commune spans an area of 1,455.3 km². Acc…Cabildo is a Chilean city and commune located in the Petorca Province, Valparaíso Region. The commune spans an area of 1,455.3 km². According to data from the 2002 Census of Population and Housing, Cabildo had 18,916 inhabitants; of these, 12,453 lived in urban areas and 6,463 in rural areas. At that time, there were 9,466 men and 9,450 women. The population grew 8.0% from the 1992 census count of 17,520.