Whereas the caves have been in the area for million of years and since civilization settled also known to the local population, the first serious exploration and mapping efforts of the caves in Quintana Roo began in the early 1980′s. Since that time the Quintana Roo Speleological Survery (QRSS) has collected documentation of several hundred kilometers of submerged cave passages. These efforts have established the area as a unique karst aquifer and unparalleled in size on earth. Currently (2012) 8 of the 10 longest underwater cave systems of the world are located within this area.
The average cave depth is 12m/ 40ft with few systems being deeper and the maximum depth of 119 m/ 391 ft found in the pit area of the Dos Ojos cave system. Explorers have also discovered diveable passage which link several cave systems to the Caribbean Sea. The first caves explored were those with easy road access. Now much of what remains to be discovered requires further penetration ito the thick jungle where remote cenotes pose increased logistical challenges.
(copied from the APSA Cavern Guide Manual, 2003 and information of caves updated to 02.2012)