CAVES ARE UNDERGROUND PASSAGES AND CAVERNS CARVED BY WATER AND LAVA. In their relatively undisturbed interiors, dripping water and volcanic activity deposit minerals that can form stalactites, stalagmites, and crystals.


Mexico’s unearthly Cave of Crystals looks like the inside of a geode. The hot, crystallized cavern lies deep underground, near a magma chamber, and some of its transparent crystals are more than 35 feet (11 m) long.

Troglobites, troglophytes, and trogloxenes are creatures who hang out in caves. While troglobites such as blind fish must spend their entire lives in caves, troglophytes are able to creep out ...

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