The SCI Serra da Estrela is a orographic accident that, along with Serra do Açor and Serra da Lousã, forms the far west side of the central range. Five distinct landscape units can be found there: the central plateau, the peaks and some crests stretching from it, the lower altitude plateaus, the slopes and the valleys with the water courses. On the SCI we can find the highest place in Continental Portugal and an important part of three of the main Portuguese river basins — Douro, Tejo e Mondego. The mountain upper landscape suffered a strong influence from the Quaternary glaciation and presents a peculiar morphology. The SCI includes a diverse habitat mosaic, joining several elements, which are representative of different biogeographical regions. It is, as to be expected, the most significant area in Continental Portugal regarding natural values — many of these unique — associated with high altitudes.