Are you a little claustrophobic? Me too. Yet I have no problem what so ever dropping down into a hole in the ground filled with cold, crystal clear water and swimming like a fish. Love that cenote experience!
If you don’t have a Mexico “to do” list you need one, and swimming in some of the marvelous cenotes in the Cancun area needs to be at the top of that list.
The Yucatan Peninsula is home to literally thousands of them. They are limestone sinkholes filled with water. To the Maya they were sacred sources of desperately needed fresh water, revered and thought of as entrances to the underworld.