Diving in the Yucatan Cenotes, Riviera Maya.
A cenote (pronounced in Mexican Spanish [se-no-te] from Yucatec Maya dzonot) is, in the Yucatán Peninsula, a type of freshwater-filled limestone sinkhole. The term is also nowadays increasingly used to describe similar karst features in other countries such as Cuba and Australia, in addition to the more generic term of sinkholes. As cenotes are filled with groundwater, water flow through them may be very slow, of the order of 1 to 1000 meters per year. In many cases, the cenote is known to connect with an underlying cave system and the water flow rates through the cave may be much faster, 1 to 1000 meters per day. Cenote water is often very clear and fresh, as the water comes from rain water infiltrating slowly through the ground, and therefore containing very little suspended particulate matter. Cenotes around the world attractt cave divers since many of them are entrances to underlying flooded cave systems, some of which have been explored for lengths of 100 kilometers or more.