The blue-and-white-tiled Santa Marta Lighthouse, completed in 1868 on the headland that closes the south end of Cascais Bay, is one of the prettiest lighthouses on the Portuguese coast. The lamp still operates as a working aid to navigation for the marina, but the keeper's house has been converted into a small museum.
The exhibits cover the history of Portuguese lighthouses, the optics and lenses used over the centuries, and the day-to-day life of a keeper. Climbing the tower is included with the modest entrance fee, and the views over the marina and the Atlantic are excellent. The lighthouse is right next door to the Casa das Histórias Paula Rego — they make a natural pairing.