There is a C-123 in Quepos, used as a restaurant / night club.
There is a also cultural center in what used to be an airport, near the capital, San Jose.
http://www.mopt.go.cr
At the Tobias Bolanos airport, you can probably see the Cessna O-2s, DHC-? Caribous and helicopters belonging to the Public Safety Ministry, but I have no idea of how restricted the access is at this time.
More than aviation though, you will find that Costa Rican women are really beautiful, well educated and friendly.
Good luck, and enjoy your stay in Costa Rica.
Saludos,
Tulio