Fortress of Solitude: Mexico's Crystal Cave of Giants

I've been in a real-life "Bat Cave." I've sat in the captain's chair on the set of "Star Trek: Voyager." I've even walked amongst hills where Iron Man would later escape from terrorists. But I've never been inside Superman's Fortress of Solitude.

Turns out such a place does exist outside of movies and comic books. In a mine in the Chihuahuan Desert of Mexico, miners discovered in 2000 what could be the world's largest crystals. Giant columns of selenite (gypsum) grow as long as 50 feet, conjuring visions of the Man of Steel's hideout.

For now, the 1,000-foot-deep "Crystal Cave of Giants" is off-limits to the general public. But perhaps one day these amazing crystal behemoths will be accessible to everyday adventurers seeking a crystal connection to Krypton.