With the opening of the new international airport at Liberia LIR in Guanacaste, you can now fly from many US gateways including Dallas, Houston, Miami and Atlanta directly to Guanacaste. From there you can drive or fly to all Pacific beach cities in a few hours.
To access Guanacaste's beaches from San Jose, a ferry can be taken from Puntarenas, a hot town with about 40,000 inhabittants, to the other side of the Golfo de Nicoya. From there, a long ride on poor pavement can take you to any number of great beaches. However, skipping the ferry and instead taking the Puente de la Amistad literally "Bridge of the Friendship" is probably preferable. It's about four hours to most Guanacaste beaches from San Jose by car a little bit more by bus.
