Mexico Ik-Kil Cenote

Swimmers float in the sapphire waters of the Ik-Kil cenote, near the Maya site of Chichén Itzá in Mexico’s Yucatán Peninsula.  Cenote is Spanish for “natural well”.  Sinkholes at sea level fill up as high as the water table, creating the famous clear blue pools used by Maya royalty for relaxation and ritual sacrifice.
photo source: Cenote