While I love the 3 cenotes of Chunkanan (aka the Cuzama cenotes) and they are indeed magical, potential visitors should know that this attraction is in the midst of some serious problems that will come as a rather unpleasant surprise unless you read this update.
Initially started as an attraction based in the village of Chunkanan, the folks from nearby and larger Cuzama realized that many tourists passed their town without stopping and decided they wanted a piece of the pie as they alleged that one of the cenotes was on their land. They therefore created their own access to the cenotes, building a rail track that intersected with the original tracks from Chunkanan. This caused some conflict, but after a few fisticuffs and much negotiation, an uneasy truce was arrived at.
At the Cuzama entry point, red-flag waving men attempt to make tourists stop, telling them that the other entry point is "closed". Just beyond them are green-flag waving people from Chunkanan waving to continue on to their village and take the tour from there.
Now it seems that the even larger village of Acanceh, the one before Cuzama (are you still with me here?) has gotten into the act, alleging that one of the cenotes is actually on their land and, since Cuzama was collecting a "fee" from the Chunkanan folks, has asked the Cuzama people to hand over a portion of that "fee". Cuzama has so far claimed that this is not correct and they will hand over no funds to Acanceh. Acanceh has retaliated by not allowing access to "their" cenote.
Therefore, there is no access at the time of this writing to the last - and most spectacular - cenote, the one with the vertical ladder down a small tunnel-like hole. According to the folks from Cuzama, when asked, the cenote is having some "maintenance" done. Not true, according to a Chunkanan rail cart driver I talked to who then went on to explain the whole thing.
A last report from a tour guide in the field one week ago, states that the Chunkanan folks are now offering only ONE cenote - the first one, Chelentun - while the Cuzama folks are taking their tourists to "their cenote" which is the middle one for those who have been before.
So if you are planning to visit Cuzama/Chunkanan for the "three" cenotes, be aware that you may not visit all three, or even two, of those magnificent cenotes until someone steps in and mediates a solution that will bring the tour back in a manner fair to all parties involved.