The cenotes are a natural pit, or sinkhole, resulting from the collapse of limestone bedrock that exposes groundwater underneath.
These were sacred places among the Mayan civilizations as they play a vital role on the community. The mayans cenotes were a channel of communication between the living and the gods of the infra-world, as the abysm represented a mouth. They were also the source of clear water, as well as a sacred place of worship, offerings and sacrifice.
In some cenotes there is fresh water on the top, and salty water on the bottom, creating a trouble zone where the waters mix, this is called “halocline” and it causes an unexpected temperature change called “thermocline”.