Divers are especially fond of this aptly named bottomless, crystal-clear cenote leading to caverns that seem to have no end. Snorkelers can follow the dive lights into caves close to the surface and see fantastic stalactites and stalagmites.  Since it’s off the main highway, this fabulous cenote is less popular with groups and feels like it’s buried in jungle. The nearby Temple of Doom, also called Calavera, or Skull Cave, is marked by a small sign in front of a ramshackle house. The cenote is located in the back yard, and accessible only by an eight-foot jump into the water, or a rusty ladder that also comes in handy for the return climb.