The long history of Barreiros has left an important legacy of archaeological remains, among which the most numerous are the castros (fortified settlements, mostly pre-Roman). There are a total of nine, five inland and four on the coast, of which perhaps the best known is the one at Punta do Castro, next to Arealonga beach, whose occupation is estimated after the 1st century A.D., and where the walls and moats can be seen. In it, among others, bronze objects, a fibula and ceramic remains appeared, as well as an interesting shell deposit related to the possible obtaining of the precious purple colour for the Romans. Usually these structures aren’t excavated or partially destroyed by human action and, in the case of the coastal castros, by marine erosion.

Apart from the abundant castros, in Barreiros we have singular elements of the archaeological heritage such as the Círculo Lítico de A Roda (A Roda’s lithic circle), which is about 4,500 years old and was the first to be found outside the British Islands; or the Coto beach Medieval Tomb (carved in the rock). Other less accessible examples are: the Penabor dolmen and the Insua megalithic tumulus, both recently discovered; O Campo de As Fachas tumuli and necropolis of cists in San Xusto de Cabarcos; the Regodomel and Fonte dos Trobos-Chivadoiro tumuli, in San Miguel de Reinante and San Xulián de Cabarcos respectively; or the As Covas Roman mine.

All of them remains that strengthen the culture of our village.