The closest airport to Costa da Caparica is Lisboa airport, served by most major airlines including the TAP and the low costs Ryannair and Easyjet
http://www.ana.pt/portal/page/portal/ANA/AEROPORTO_LISBOA
Costa da Caparica is only 22 km south from the airport. But it is the other side of the river, in a location comparable to Ocean Beach in San Francisco.
The fastest trip from the airport is by car or taxi. Taxi drivers are nicer at the departures than at the arrivals (you have to go 1 floor up in the airport). But taxi costs ~ 40€. If you mentioned your arrival time in your registration, and if other particioants arrive at the same time, we will email you and the colleagues who may possibly try to share a taxi with you.
The lowest cost option is to catch a suburban bus.
- To connect the suburban bus from the airport the easiest it is cheaper to catch a city bus ~2 € or a couple of metros ~2 €; the first stop of 161 TST suburban bus at Areeiro 3 km straight south of the airport, but notice the metro takes a large detour to arrive at Areeiro
http://www.metrolisboa.pt/Default.aspx?alias=www.metrolisboa.pt/eng .
- the 161 TST suburban bus, starts at Areeiro, 3 Km south of the Airport, and then has several other bus stops in Lisboa,
http://www.tsuldotejo.pt/index.php?page=viajar&sub=viajar&categoria=2&subcategoria=6&carreira=882 .
- The Hotel Ever Caparica is at 500m, walking distance, of the 161 TST suburban bus station,
http://everhotels.com/caparica/en/hotel-overview.html
Have a nice travel !
