We cycled about an hour to get to Grand Cenote, a limestone sinkhole that reach a vast network of underground rivers and streams in the Yucatan, may have been formed by a comet that wiped out the dinosaurs 65 million years ago.
The road right by where we stayed.
Inside the Grand Cenote.
Water is extremely clean and cold, you can swim with tons of small fish and some turtles.
From outside of the Cenote. It's about as deep as 2-story house below the ground to the surface of water, and some part goes up to 10mm depth.