Castelo do Casón is a medieval archaeological site of significant heritage value located on Mount Casón in the Sierra de Capelada, Ortigueira, A Coruña. Perched at 291 meters above sea level and overlooking the Ría de Ortigueira, the fortress features remains of walls and moats indicating a High Middle Ages construction, possibly built over the ruins of an ancient castren settlement. Initially classified as a prehistoric castro, ceramic evidence confirmed its medieval origins. The site has been opened to the public with guided tours allowing visitors to observe ongoing archaeological investigations and learn about the fortress's strategic importance in medieval Galicia.