Cenote the Pit its located about 20 km north of Tulum town. Its a deep sinkwhole of more than a 100 mts (300 feet) deep. The clarity of the water allows sun beams to go as far as 35 mts without being refracted.
Floating through it gives a strong sensation of floating in space or lacking gravity for a while.
The stalactites hanging from it are the celarest evidence of its dryer stages, down to even 70 mtes less than its current stage.