In this beautiful valley in front of Rocha da Pena there are different records of the Silves Group, from the Pelite Units with evaporites and carbonate intercalations to the Volcano-sedimentary Complex with a predominance of pyroclastic material such as breccias and volcanic tuffs that indicate that the volcanism was explosive.

This complex is composed of sediment originating from fissure-type continental magmatism, which corresponds to the first phase of opening of the Atlantic Ocean and the associated intense volcanic activity 195-190 million years ago.