For sweeping views over dale and coast, roam the snaking ramparts of the Moorish castle, rising 200m above Sesimbra. It was taken by Dom Afonso Henriques in the 12th century, retaken by the Moors, then snatched back by Christians under Dom Sancho I.
The ruins harbour the 18th-century, chalk-white Igreja Santa Maria do Castelo (9am to 4pm); step inside to admire its heavy gold altar and exquisite blue-and-white azulejos. The shady castle grounds are ideal for picnics, and a few small historical exhibitions offer brief distractions. There's also a tourist information point for Geocircuito de Sesimbra (www.cm-sesimbra.pt/geocircuito), which highlights important geological discoveries in the region. To get here from town, any outbound bus can drop you at the start of the pedestrian path, a 1km walk up to the Castelo.
