They are very close to each other... rent a car, much easier to get around that way. Cars are cheap to rent, we paid $142 total for a 7 day car rental with Alamo. Go to Riviera Maya... Play de Carman (spelling?) is very close and has things to do for the non-partier / non-diver! Both, cancun and Riviera Maya are about 20 minutes from the Airport (in oppisite directions). When are we going diving????