The Best Sight in Sintra, Sintra, the Estoril Coast, and the Setúbal Peninsula

The battlemented ruins of this 10th-century castle still give a fine impression of the fortress that finally fell to Christian forces led by Dom Afonso Henriques in 1147. Panoramic views from the serrated walls explain why the Moors chose the site. It's visible from various points in Sintra itself, but for a closer look follow the steps that lead up to the ruins from the back of the town center (40 minutes going up, about half that coming down). No cars are allowed, but you can save your legs by catching Scotturb Bus 434 or taking a tuk tuk ride from town. The castle is walkable from the Palácio da Pena, since it's accessed from the same road and its entrance is somewhat below that of the Palace park.