Head north from Jaco, go past the road to Los Suenos. Go up the mountain maybe a few miles and it should be the first left and there will be a sign for Villa Caletas hotel and restaurant. The drive up the "hill" to the place is LOCO!... and beautiful. Its incredible.
About half way (2 1/2 hours) from San Jose to Jaco is Puntarenas. A nice place to stop and have a bite.