Cenote
From Freepedia
Image:Sacred-cenote.jpg Cenote (pronounced say-no-tay, plural: Cenotes) is the name given in the southern part of Mexico and Central America to freshwater-filled limestone sinkholes. Cenotes are fully or partially collapsed karst caves. Mature cenotes often resemble small, circular lakes or lagoons with vertical edges. The name cenote derives from Mayan language dzonot.
Cenotes have long been major sources of water in much of the Yucatan peninsula, most of which lacks other easily accessible year-round water. The Maya city of Chichen Itza was built around a cluster of these natural wells. Some cenotes like the Cenote of Sacrifice in Chichén Itzá played an important role in Maya rites. Golden sacrificial artifacts were found in such cenotes, leading to the archaeological exploration of most cenotes in the first part of the 20th century.
The cenotes provide access to extensive underwater cave systems. These have attracted cave divers and there are organised efforts to explore and map the underwater systems. Diving in cenotes can be very dangerous and several divers have died. It is easy to become lost in the passageways, and visibility can easily be lost if silt is disturbed. Open water divers should never attempt to dive a cenote without proper cave/cavern training and certification. In addition to the training divers also need special equipment to dive with any degree of safety. This includes multiple powerful lights, twin tanks and twin regulators. Divers follow what is known as the rule of thirds. This means that after one third of a divers air is used he or she must turn back; leaving one third of the air for the return, and one third in reserve.
