Mexico holds many enchanting destinations south of the border, including this underground river where you can swim in a cave ...
See the most popular Photo of the Day images from March, featuring a landscape of Toad River valley, Chicago city lights, a crystal cave, and more.
The Cave of Crystals, also known as the Giant Crystal Cave, is a cave connected to the Naica Mine at a depth of 300 meters (980 ft) in Naica, Chihuahua, Mexico. It takes the form of a chamber ...