Castro de Borneiro

Castro de Borneiro is an archeological site in Galicia, Spain. A castro is an iron-age walled settlement, or oppidum, and the site is an example of remnants of the Castro culture in Northern Spain which dates as far back as the 9th century BCE, though this site was inhabited from the 4th to the 1st century BCE. It is a textbook example from that period, and has been the focus of several excavations and alterations to accommodate visitors.

Source: Wikipedia