The Yucatan Peninsula lies on a limestone platform, which was formed millions years ago. During several Glacial periods Ocean levels varied greatly.  At different eras this region found itself submerged under water and at other times above the Ocean surface.  During lower water level periods is when the caves were formed. Heavy rains fell on this rock plain and since there are no mountains the water was able to seep into the ground absorbing Carbon Dioxide from the soil and decaying plants. This mixture is known as Carbonic acid and is able to dissolve the weaker rock creating large underground voids and passages as the water finds its way to the sea.  In this process, Speleothems (stalactites, stalagmites, flowstone etc.) were formed in the passages as the “liquid stone” re-solidified creating a magical environment beyond description.

During the last Ice Age, Ocean levels were 300 feet (100 meters) lower than today. Approximately 18,000 years ago the ice began to melt and eventually rose to its current level, flooding the passages and creating a massive network of subterranean rivers unlike anywhere else on Earth.