Selvatica

Jungle adventure located about 30 minutes south of the Cancun Hotel Zone.  The tour is centered around zip-lines (steel cables strung from tree platform to tree platform on which one rides in a harness connected to cable rollers) and swimming in a cenote (sinkhole).  

There are 12 zip-lines that you go through, which takes about an hour.  The cenote lasts about 45 minutes.  Then lunch, and watching the dvd of your trip.  Overall, allow about 6 hours or so, including travel-time.   There is also a "night-flight" trip option, which obviously is at night.  The cost for that one depends on the meal you choose.  Don't forget to pack your insect-repellant, because you will be up in the forest with lots of bugs.  Not an issue if you have repellant, though.  There is a locker you can keep your items at during the zip-line.  If you want to try to go upside down, ask for "a cabeza".  :)