The Yucatan peninsula was originally under the ocean and the region's limestone foundation is fossilized coral beds and ocean floor. There are no above ground rivers in this area.  All of the ground water sinks through the porous limestone and travels to the sea in underground rivers. Parts of the limestone weakened over time and collapsed, leaving sinkholes filled with water - a cenote (pronounced: seh-NO-tay).

During the ice ages, portions of the underground rivers dried up and water dripping through the limestone left mineral deposits in beautiful formations. Stalactites and stalagmites formed in the caves and caverns, and were covered with water when the rivers began flowing once again.

The Maya used the cenotes for water - both for drinking and irrigation - and in religious ceremonies. Some of their cities were built around cenotes or wells dug down to the ground water.  Divers have explored the cenote at Chichen Itza and have found offerings the ancient Maya made to the gods. Among them copper and gold necklaces, pottery, jade beads,  and skeletons of both sexes and all ages.

Today at least 1000 cenotes have been located among the approximately four thousand that are believed to exist in the Yucatan. These unique places are now included in the ever increasing number of tourist attractions of the area, both for the archaeological value they offer and for the exquisite natural beauty they possess.

Descriptions of some of nearby cenotes (in order of distance from Cancun):

Boca del Puma:  Located in the Boca del Puma Eco Park, situated 16 km west of Puerto Morelos.  This cenote is located in a private eco-park that offers tours that include a zip line, bicycle riding, and a swim in a cenote.

Cenote Verde Lucero:  Located in the Selvatica Eco Park, 18.5km west of Puerto Morelos. Selvatica offers zip lines, horseback riding, cenotes, and snorkeling.

Sistema Xcaret:  Located in the Xcaret Eco-Park, 6.5km south of Playa del Carmen. Here you will find archaeological ruins, a dolphin show, horses, a farm with tropical birds, butterflies, bat caves and a stunning beach. You can go also snorkeling in the famous caves and the well known underground river. With its 53 activities to enjoy, Xcaret is an experience for all your senses.

Cenote Chac Mool: Located 22 km south of Playa del Carmen (near Puerto Aventuras). It includes two separate cenotes, with snorkeling available in the larger of the two.  There is a large cavern zone with beautiful views of the jungle from inside the cavern. A restaurant and bathrooms are available at the site.

Sistema Ponderosa - Cenote Eden:  Go exactly three kilometers south of Puerto Aventuras on Highway 307 or 13.0 kilometers north of the Akumal C.D. entrance. Take dirt road going west up over hill past the power lines 1 kilometer. Sign in at gate through local dive/snorkel businesses. Drive one kilometer to parking area. Includes 13 cenotes within the cave system, including Cenote Eden, Cenote Uchil Ha, Cenote Cristalino, and Cenote Azul. Wide cement steps and platform leading from parking area down to the water. Well maintained foot paths around the cenote and surrounding property. Public toilets available

Sistema Aktun Koh:  The road entrance is 3.9 kilometers south of Puerto Aventuras or 15.4 kilometers north of Aventuras Akumal. West side. Follow Rough road going west for 2.5 kilometers to the very end. Includes Cenote Actun Koh, Cenote Bear's Den, Cenote Overpass, Cenote Foxhole. This is a popular commercial snorkeling site for tourists.

Sistema Taj Mahal:  From Puerto Aventuras drive south on Highway 307 5.5 Kilometers or from Aventuras Akumal drive north 13.8 kilometers. Entrance on west side of highway at the tourist shop selling blankets and crafts. Pay dive site fee inside. Take dirt road back into the jungle and Drive 1.9 kilometers to the very end. Parking area. No public toilets. The cave system includes six cenotes: Cenote Taj Mahal, Cenote Sugar Bowl, Cenote Mangrova, Cenote Buena Vista, Cenote City of Agra, and Cenote Sacrada.

Sistema Aktun Chen (Wood Cave):  Located 40 km south of Playa del Carmen. This cave system includes nine cenotes, including cenote Aktun Chen.  Canopy Aktun Chen is a tour operator offering a cenote and cave tour, as well as zip lines.

Sistema Alhambra (White Castle):  Go to the Playa Aventuras (DIF) entrance, Go west through gate on dirt road for the Actun Chen dry cave and drive approximate 1.0 kilometers to the power lines, Turn left and follow trail 200 meters to the first power line tower, Park vehicle and follow trail 50 meters to the cenote.

Xel-Ha:  Located 48 km south of Playa del Carmen. Xel-Ha is an eco-park in Riviera Maya renowned for its stunning natural aquarium. Xel-Ha has the Cenote Paraiso and Cenote Aventura on their grounds. At the park you can enjoy with your family or friends, an array of water activities and both natural and ecological attractions. Or alternatively, simply relax on the tranquil lazy river as you sail along on a comfortable inner tube.

Dos Ojos:  Located on the highway between Akumal and Tulum.  Part of Nohoch Nah Chich cave system. This was the location of filming for Imax Journey into Amazing Caves documentary. Very popular. Many stalactites & stalagmites. Dos Ojos is located in the Hidden Worlds Cenotes Park.

Casa Cenote (also known as Cenote Manatee):  Located 11 km north of Tulum in Tan Kah.  The cenote itself is actually pretty easy to get into and out of, and the calm and clear waters are fun for kids. Casa Cenote is actually very close to the ocean, and has a connecting tunnel to the Caribbean. Although swimming in the connecting tunnel is not suggested, it is interesting how the salt water comes into the cenote and mixes with the fresh water. There is also an ocean-view restaurant between the cenote and the Caribbean.

Calavera Cenote:  Located 3 kilometers from Tulum on the road towards Coba right side.  Probably the most dangerous cenote in the area. Calavera is easy enough to get into by jumping in. However, getting out can be a problem because of the ten foot drop from the cenote rim to the water. Exit can usually be made using an existing tree branch, or by bringing a rope.

Cenote Abejas (Bees):  Located 2.3 kilometers north of the intersection going to the Navy Air Station and the Tulum Aquario Hotel or between kilometer 232 and 233 on the east side of Highway 307.  Pay at the gate.

Gran Cenote:  Tulum. Right off of Highway 307 when you get to the second traffic light in Tulum. You want to head towards the Coba ruins, and go about 3 kilometers where you will see a sign for Gran Cenote on your right.  A collection of several cenotes around the edge of a large oval depression. These cenotes offer shady and rocky floors, green and blue water, and some stalactites dripping from the cave ceilings.

Car Wash Cenote:  Located 7 kilometers west of Tulum on the road to Coba left side.  A fun cenote for swimming, snorkeling, and diving. You can drive in (about 30 meters or 100 feet) right up to the cenote (hence the name). There is a diving platform on the edge that makes swimming a breeze. Many small tropical fish inhabit the cenote.

Systema Naharon - Cenote Cristal:  Located 4 kilometers south of Tulum, on the way towards Chetumal.  This is actually 2 cenotes, cenote cristal and cenote escondido, one on the left side of the highway and one on the right side. The entrance fee includes access to both cenotes. The larger of the two pools is about an acre in size, with much of the access up a 18 foot cliff, or on the far side via the vegetation.

Cenote Azul:  Located well south of Tulum, approximately 20 miles north of Chetumal and across Chetumal bay from Xcalak near Bacalar. Cenote Azul is a pit cenote. In fact, it's the largest pit cenote in all of Mexico, 600 feet across and more than 290 feet deep. It is a spectacular cenote in a beautiful garden setting. Snorkeling the rim is quite interesting, although the bottom can only be seen with Scuba gear. A restaurant is located right on the edge of the cenote, and is a great place to relax in the cool shade.