If you're gonna do anything in Mexico I highly advise to go see the ruins. They are one of the seven wonders of the world for a reason.
Xplor Park
Cancun, Mexico
If you're looking for adventure this is the place for you. You can do it all here at the Xplor Park in Cancun. From ziplining, swimming in the cenotes, and even being able to cruise through the jungle on ATV's. This park also offers a night time experience.
5th Avenue
Playa del Carmen, Mexico
If you are wanting to do some shopping and bargaining 5th avenue in Playa del Carmen is the place for you. Plus they have some amazing restaurants, bars, and nightlife here to get a feel of the local flavor.