The Arca da Piosa is one of the biggest megalithic monuments of all of Galicia and one of the most well known. It was described by Manuel Murguía in his “Historia de Galicia en 1903” [History of Galicia in 1903] and by Saralegui y Medina in the work “Megalitos de España” [Megaliths of Spain] in 1925. However, the most well-known reference is a poem that appears in the work of Eduardo Pondal “Queixumes dos Pinos” (1886). Pondal sought to glorify Galicia’s past, taking the Celtic world as a reference for this. In the work he converts certain place names and parishes of the Costa da Morte into mythical heroes and thus the Arca da Piosa appears as the tomb housing the body of the warrior Brandomil.

Arca antiga da Pïosa,
O vento q' he triste oir,
Funga nas esquivas uces,
Q' están o redor de tí;
E pasa antr' elas bruando,
Con un dorido gemir:
Debaixo das tuas antes,
'Stá o valente Brandomil;

Ancient ark of A Piosa,
the wind, that is sad to hear,
hums among the aloof heathers,
that are around you,
and passes among them roaring
with a painful groan,
under your dolmens
is the brave Brandomil

The megalith’s dolmen is quite well preserved, as is the volume of the mámoa covered by a stone cairn. In the inside of the chamber and passage, vestiges of prehistoric red and black paint can also be found on 3 of its stones, as well as a cross—probably modern, etched into its capstone.

An interesting fact is that the main material of the dolmen is gneiss, a type of stone which is found over a kilometer and a half away. This gives us an idea of the enormous amount of work undertaken to move these slabs, each weighing over 6 tons, over such a long distance.