From the Monte de Eiró (parish of Penhalonga, Marco de Canaveses), this stone was part of a boulder complex from which it was cut. It is a rectangular-shaped granite monolith decorated with geometric representations, two spirals and wavy, serpentine lines. This type of engraving was made by rubbing and picking with stone incisors.
In 1910, the stone was transported by boat, along the River Douro, to the Municipal Museum, where it remained until becoming part of the municipal collections in the Soares dos Reis National Museum.