The mystery of “The Thing” inside the dolmen
Pedra da Arca is one of the largest megalithic monuments in Galicia and stands out for its excellent state of conservation. In fact, it maintains most of the dolmen, the chamber, its corridor and also the tumulus or mámoa that covered the burial.
The megalith is located right on the dividing line between the parishes of Baíñas (Vimianzo) and Olveira (Dumbría) and for this reason, both in the chamber and in the stone of the roof, two boundary crosses were engraved, already in historical times, indicating its function as a border mark.
Inside the chamber there are remains of prehistoric red engravings and paintings. The most outstanding motif of those preserved is a design also located in the dolmen of Dombate (Cabin of Bergantiños). Irish archaeologist Elisabeth Shee called it “The Thing”, a term that would eventually become popular to this day. Although some researchers have interpreted this figure as an axe or even as a sperm whale, the truth is that the meaning is unknown. However, their relative frequency within megalithic chambers suggests a design of high symbolic value during the megalithic period.
A curious fact is that the dolmen is built with three different types of rock, all present in the vicinity except for the slab on which the engravings appear, which is made of granodiorite and had to be transported from three kilometers away.