Castro de Santa Trega is a Galician fort located at an altitude of nearly 350 m above sea level on the edge of the Santa Tecla mountain. Established around 100 BC. The object has the status of a national monument. This well-preserved Castreno-Roman city impresses with prehistoric petroglyphs and superbly restored residential buildings characteristic of the Castro culture. From the fort there is an amazing panorama of the mouth of the Miño River and the Atlantic Ocean.
Castro de Santa Trega was discovered in the first half XIX century during the construction of the highway. An excavation site was created in the exposed area. Regular work was supervised by the famous Spanish archaeologist Ignacio Calvo Rodríguez.
The city located in Galicia probably arose in the Bronze Age. Castro de Santa Trega had a population of nearly 300 people. Its inhabitants mainly dealt in agriculture, shepherding and fishing.