The castro hillforts of Galicia

From about the 9th century BC the peoples of north-west Iberia lived in castros, hilltop villages of round stone houses ringed by ramparts and ditches; thousands are known in Galicia. After Rome conquered the region under Augustus some, such as Santa Trega, grew into larger towns before being left for the valleys. They underpin modern Galicia's sense of a Celtic heritage, a label scholars still debate.