These eerie outliers of the lightning bug family glow a mysterious blue color.

A collection of Witchcraft artifacts and occult paraphernalia started by the leader of the Long Island Coven.

No one knows how this Pacific Northwest spruce tree came to have so many trunks.

The scuba diving training facility was named for the steam that rises from the cave's chimney.

Wild lights and sound effects turn a walk through some caves into an eye-popping 1960s tourist attraction.

An underground mansion with fruit-bearing trees and grapes growing beneath the surface of central California.

One part antique store, one part curiosities hodge-podge.

A hotel and restaurant serving as the mecca of kitsch.

It's not hard to see why the historic Peabody Conservatory of Music's library has been described as a "cathedral of books."

The angel of death appears to weep black tears at this grave marker.

All that's left of the quintessential "cabin in the woods."

A stunning, two-tiered waterfall made famous by poets, artists and the legend of a ghost dog.

This natural wonder drops 16 stories straight down through rare flora and streaming waterfalls.

The world's longest known cave system.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.

This geothermal hot spring hides beneath a slowly growing mineral dome.

Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

This frequently-photographed waterfall takes only a short hike to visit.

There is no trying to fall in love with this Star Wars fountain, you just do or do not.

A library of rare occult books in Los Angeles.

Where beautiful signs live on forever.

Seemingly grown on some other world, these New Mexico rock formations look like a disused science fiction set.

Home to items never before seen by the public.

Where manatees are the snowbird vacationers in these balmy Florida springs.