Ik-Kil Cenote, Mexico I have been here! It was beautiful! Swimmers float in the saphirre waters of the Ik-Kil cenote, near the Maya site of Chichén Itzá in Mexico's Yucatán Peninsula. Cenote means "natural well" in Spanish.
Jacob's Well -- Wimberly, Tx: One of the most significant natural geologic treasures in the Texas Hill Country. It is one of the longest underwater caves in Texas and an artesian spring. Jacob’s Well surges up thousands of gallons of water per minute.
"This is Flathead Lake in northwestern Montana, USA. The water is so transparent that it seems that this is a quite shallow lake. In fact, it is feet deep." It's not Flathead Lake unfortunately! It's Avalanche Lake :)