The fault of Felgueira-Preguinho is a vertical gap responsible for the difference of 255 meters between the Freita mountain block (highest point: 1085 meters) and the Arestal mountain block (highest point: 830 meters). This is oriented NW-SE, and causes the abrupt slope of southwest Freita mountain. Its importance is related to the influence of tectonics on landscape formation that is observed here. The Paraduça stream, Teixeira’s affluent, takes the fragility of this failure to dig its valley, separating clearly Freita from Arestal mountains. This geosite located in a place called Rocha da Cabeça (head rock) by having a privileged view to the Felgueira-Preguinho fault, which begins precisely in the village of Felgueira. The granite outcrop presents some pedras Boroas (maize bread stones) and old marks of artisanal use of this rock.
