Burgos overlooks the banks of the Arlanzon, close to the Iberian mountains, in the region of Castilla y León. The town was founded in the 9C and was the birthplace of Castile, becoming an archdiocese in 1574. Between 1936 and 1939, Burgos was the headquarters of General Franco's Nationalist government. The old town lies on the west bank and a modern district has been built on the east bank. Burgos is famous for its cathedral, one of Spain's finest Gothic buildings.