20 km away from Lisbon, on the left bank of the Tagus, lies Costa da Caparica, the most popular beach resort in the region. Basically it's an extension of sand some 20 km long that ranges roughly from the mouth of the Tagus river to Praia do Meco.
Costa da Caparica is also the name of the village that lies near the north limit of this strip of sand. The beachfront of the village is divided by a succession of jetties in several narrow beaches, and a number of quality waves can be found here. It's difficult to say which of these beaches has the best surf; since all of them have sand bottom, conditions are constantly changing. The best strategy is to check out the whole beachfront to see where the best conditions are happening.
A number of surf shops can be found in the village and nearby and there's a regular bus service to and from Lisbon. There are also several camping sites.
It's also a good idea to visit the nearby beaches to the south of the village. In fact, conditions there are sometimes better than in the village's beachfront. Many surfers prefer to surf there because the lineup in front of the village can be quite crowded, especially during the summer.
If you're planning on coming here in the summer note that it can be quite a challenge to cross the 25 de Abril bridge which connects the west of Lisbon to the left bank of the Tagus. So be sure to get going early.

Panoramic view (~114KB)
WQS 2001