The Serra de Sintra is a granite block forming a mountain barrier, where the rains from the ocean are concentrated. This micro-climate is in stark contrast with that of the surrounding area and is the reason for the dense vegetation that covers the whole of the massif. The great wealth of the ecosystem and the mistily romantic veil that emanates from it have been celebrated time and again by poets and, in particular, by Gil Vicente, Camões (The Lusiads), Southey and Byron (Childe Harold's Pilgrimage).