The Pedras Boroas (cornbread rocks) are the result of different erosion process that granite suffered and which highlighted its basic structure. This phenomenon gives rise to the formation of a network of polygonal cracks in the eroded rock resembling, to the naked eye, the surface of a boroa (typical cornbread), so the rock was named. The Pedras Boroas do Junqueiro are an important geosite from Arouca Geopark that fall into a residual granite relief of the Freita mountain, outcropping in the uplands of Albergaria da Serra. The erosion that causes this pattern has resulted from the harsh climate with significant thermal range that is felt on the top of the mountain. This plateau is marked by a stunning landscape where pastures and moors alternate with peat bogs (very rare and protected habitat), which are formed in the vicinity of streams that feed the Caima river.
The great wealth of this granite plateau are undoubtedly the peat lands accompanying mountain streams, habitat of many species of flora that only grow here. Cyclamen-flowered daffodil, the cross leaved heat, the matgrass and the marsh gentian are some of the species that characterize this rare ecosystem. Some dragonfly species, the european tree frog, western three-toed skink and the blue rock thrush are also frequent on this plateau. The S. Pedro Velho Castle Kopje – geosite from Arouca Geopark – is a residual granitic relief of the Freita mountain, and marks its highest point at 1077 meters. For its altitude, grandeur and position it occupies in the mountains, this point is well visible from practically all the Freita’s plateau and reaches, in a clear day, about half of continental Portugal, from the Gerês mountain to the Estrela mountain.
The antiquity of the occupation of this plateau is attested by names like Portela da Anta. The name comes from the existence of a large mound with a main dolmen and other secondary ones dating from calcholitic period (about 4000 years ago). The dolmen consists of a ring of granite blocks based on a lithic breastplate of subcircular plant 12 meters in diameter.
