The UnXplained: Mysterious Crystal Cave Has LETHAL Atmosphere (Season 5) | History

Transcript

WILLIAM SHATNER: Northern Mexico, April, 2000. In the mineral-rich town of Naica, more than 1,000 feet below the surface of the Earth, a group of miners drilling through a cave wall make a remarkable discovery, not of precious metals, but something far more wondrous and mysterious-- a glittering cavern, untouched for half a million years, filled wi... Read More