These are incredible natural phenomena. They are huge holes in the earth which collapsed millions of years ago, maybe caused by a meteorite, and which filled up with fresh water as clear and transparent as the Caribbean Sea water. You can swim or do underwater exploring of the many grottoes, which are unique in the world. The Yucatan peninsula is full of these cenotes.
There is no area in the world with as many underwater caves as the Mayan Riviera in the Yucatan Peninsula's Caribbean coast. Playa del Carmen is the perfect place to base your vacation for a memorable cavern diving experience. Tulum and its surrounding areas are world renown for the extensive limestone cave system that lies beneath the jungle.