www.CostaRicaTicas.com

Anyone know if any airlines operate a route from Cancun to SJO? I was thinking of heading to Cancun from the US for a few days then onward to SJO for another few days and back to the US.

Nothing direct I am aware of but you can go through Mexico City or PTY, unless you want to return to US and change planes in MIA, FLL, DFW or ATL. Why not do an overnight layover in PTY?

Theoretically going through Mexico City and taking the evening Mexicana flight to SJO should be the best way to do it. I say theoretically because I've flown Mexicana from MEX to SJO three times. Twice the flight was late, getting into SJO well after midnight, and once I missed the connection and had to go the next morning.