Tulum has a very unique landscape. Many visitors come for the white powder sand beaches and turquoise waters. It is easy to miss the beautiful jungle, cenotes and lagoons in the area.
Cenotes are one of the rare treasures of the Rivera Maya. Cenotes in Tulum and the entire Yucatan peninsula are created out of the rare and breathtaking limestone base that sits beneath the jungle.
In Tulum there are no above ground lakes ponds or rivers. All of our water is under ground. Tulum and the entire Yucatan Peninsula is made of lime stone. Imagine a huge piece of Swiss cheese mostly submerged in water. These various holes and openings create cenotes and underground rivers. There are over 4,000 known cenotes in the Yucatan area, some say as many as 8,000. All of these cenotes are connected via underground waterways.
In some cases the water way is very small, just a crack- but in others the openings and passages are wide enough for divers to explore for hours as well as other snorkelers and swimmers to take a peak. Tulum has the longest mapped underground river system stretching more the 250 km.
There are 4 kinds of cenotes. There is the lake or pond like cenote. These are land level and look much like lakes found in other parts of the world.
Then there is the sink hole cenote. This is where the water level is lower then the land level. This distance can range from just a few meters to 30 or 40 meters.
Then there is the semi open or cave cenote. This is where you enter under the ground and swim or walk in. These are truly amazing to see and offer a rare view of the world under the jungle. The last type of cenote is the underground river. These are the waterways that connect each of the cenotes. These are reserved for the cave divers that come from all over the world to explore the most secretive and spectacular caves a diver has dreamed.
One amazing thing about the cenotes is how clean and clear the water is. Almost all cenotes are fresh water. There are some that are a mixture with some salt water, called brackish, a mixture of salt and fresh water. These are usually right on the coast line and are brackish because they have a 2 way feed from the sea and vise verse into the cenote. Often times this mixture can create an effect refereed to as halocline. This is when the salt and fresh water mix and create an oily effect in the water. This is a clear sign that there is an in feed to the near by Caribbean Sea.
When it rains, the water is filtered through the limestone and in the meantime gathers nutrients and minerals before dispensing into the cenotes underground. In many cases this process creates spectacular stalactites and stalagmites. These are the mineral deposits that are formed from the slow drip of mineral rich water. These stalactites grow very slowly, only 1 cm ever 100 years. The oils from human hands and products damage this natural growth process which is why we are all a little crazy about visitors not wearing products into the cenotes. Some of the busier cenotes even have showers for you to rinse before going in. If you are at a cenote and NEED to use a repellent (because… we get that.) Please use a bio degradable – eco friendly product.