Also called the Cuzama cenotes, these are very popular at the time of this writing (2013) and it is not recommended - by me - to visit them on Mondays unless you are part of a cruise ship excursion (you have no choice, really), or on weekends and Mexican holidays. There is no limit to the amount of people the folks in the village of Chunkanan and Cuzama will take into the cenotes and the resulting crowds will cause waiting and also take away from what is normally a magical cenote swim experience.
The access to the three cenotes is via horse-drawn rail platforms known locally as "trucks". Guess what language that comes from? Yeah, you guessed it.
The local gossip is that the Chunkanan folks started this tour, then the Cuzama folks got envious and wanted in so they started from their end as well. Now, the latest scuttlebutt is that the last cenote is on land belonging to the nearby town of Acanceh and so they have told the Chunkanan and Cuzama people that they can no longer access it. Too many people are trying to get as much money as they can, and what suffers is the experience. Maintenance issues are also a source of conflict as each group tosses the ball to the other. Since these three towns started the conflict, there have been fistfights between the groups at Chunkanan and Cuzama; the Cuzama folks will try to stop you on the highway so you don't go to Chunkanan but you can comfortably ignore them and continue for another 3 minutes and give the folks at Chunkanan your business as it was their idea in the first place. hat will happen with Acanceh entering the picture is anyone's guess at this moment.