Sintra, a world heritage site with its castle, palaces and gardens set in lush vegetation and enjoying ravishing views is a lovely 15 minute car drive across the mountain.
Less far in the other direction is the coastal resort of Cascais, where you will find superb beaches, restaurants, night-life and shopping, as well as a charming old town with rewarding site-seeing.
Lisbon is half an hour away, and with easy access to the motorway system, a number of other world class cultural and historic sites make an enjoyable day trip. Lisbon boasts world heritage sites, and a rich cultural, culinary and night life.
The motorway network puts the Knights Templars’ castle and chapels at Tomar and Batalha within an easy day trip, as well as the ancient university town of Coimbra. On the other directions, south of the Tagus, the beautiful Sesimbra and Arrabida area are well worth an easy day trip.