The “Pedra Má” is a corneal rock located downstream of the alveolus of Arouca, and it was formed because of the contact metamorphism exerted between the batholith of Arouca and the surrounding early Ordovician metasediments. The hardness and little deterioration of this rock has caused a bigger effectiveness of the sediment retention process in the alveolus of Arouca, contributing to the permanence of fertile agricultural land of the surrounding areas of the Arouca Monastery.
Location: Arouca
Location: Arouca
