Castile and León is an autonomous community in northwestern Spain. Castile and León is the largest autonomous community in Spain by area, covering 94,222 km². It is, however, sparsely populated, with a population density below 30/km². While a capital has not been explicitly declared, the seats of the executive and legislative powers are set in Valladolid by l…Castile and León is an autonomous community in northwestern Spain. Castile and León is the largest autonomous community in Spain by area, covering 94,222 km². It is, however, sparsely populated, with a population density below 30/km². While a capital has not been explicitly declared, the seats of the executive and legislative powers are set in Valladolid by law, and for all purposes that city serves as the de facto regional capital.