I just finished a week-long road trip down Mexico's Yucatan Peninsula in search of cenotes. We flew into Cancun Airport and slowly made our way down to the fashion hub of Tulum. There are rumored to be 30,000 cenotes in the area, but not all of them are made available to the public. Please do not wear sunscreen (unless it is bio-degradable) to the cenotes! Once you see how clear the water is, you'll be upset if it's covered with murky sunscreen runoff on the surface. My recommended cenotes for snorkeling are below:
Cenote Jardin del Eden
The Garden of Eden is an open air cenote off the main Highway 307, shortly after Puerto Venturas. There are actually 3 cenotes in a row here, Cenote Azul, Cristalino, and Jardin del Eden. We visited Azul and Jardin del Eden, and found Azul to be completely disappointing in comparison to Jardin del Eden. Azul is made up of separate small, shallow pools. It was completely crowded with screaming 4 year old kids when we went.
There was a 60 pesos entrance fee at the gate and limited rentals available. The setup of the cenote is one large oval with an area for cliff jumping and setting your towels down. I found this cenote to be the best for relaxing in the sun. No dive skin required - this cenote is plenty warm! The water is deep here, so if you're not a strong swimmer, a life jacket will make your snorkeling experience more comfortable. There are some rocks in the middle of the cenote to rest on if you get tired of swimming.
Gran Cenote, or Grand Cenote, is on the road from Tulum heading west to the Coba ruins. It was comparatively quite expensive at 100 pesos, but the experience is well worth it! This is a perfect cenote for beginners. It is dark in most areas, which can be creepy! After paying the entrance fee, walk down the set of stairs. There are rentals and lockers available.
I found the water to be cold at times, even though it was 100 degrees outside. There are bats, catfish, and 4 turtles in the water here so it is definitely worth it to rent a snorkel if you don't own one. The setup of Gran cenote is split in 2. On one side, you have more dramatic stalactites and deeper water. If you look below, you will most likely see divers. On the other side, you have shallower water and a tunnel-like appearance that will lead you to an open air area. There were lots of hanging bats on this shallow side which made for some really cool swimming.
Cenote Ik-Kil is located about 3km from Chichen Itza, which makes it a very touristy cenote. In fact, after you exit Chichen Itza, you will probably be approached by a few men trying to sell you tickets to Ik-Kil. It's unfortunate that they've made it into this tourist bomb, because it is by the most beautiful cenote I saw on this trip. Entry to Ik-Kil costs 80 pesos.
Once you arrive at the Ik-Kil parking lot, you are greeted with an almost resortesque bomb of shops, showers, etc. Don't let this deter you! Follow the sidewalks to the back of the property, where you will reach a staircase that goes down to Ik-Kil. When you're at the base of the cenote, there isn't a lot of space to put your things. The cenote itself is almost a perfect circle, and you have "land" access to about 1/4 of the circumference. There is an area where you can jump off of too! The cenote was dark, creepy, and exceptionally beautiful. The roots made it really special from the other cenotes we went to.
For a good (non-touristy) time, arrive at Ik-Kil before 11AM.