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

Hundreds of glow-in-the-dark objects light up a museum in a historic zinc mine.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

The private clubhouse for the members of the Academy of Magical Arts.

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

The restaurant keeps a hidden séance room on the second floor and reserves a table for the spirit of the former owner each night.

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

In a 345-million-year-old cave that's 200 feet underground, dinner awaits.

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

A historic neighborhood church is reborn as a psychedelic arts collective.

The largest self-built castle in the U.S., six decades in the making.

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

Odd outsider art installations surround a Gold Rush-era ghost town.

Strange red rock formations that have been attributed to a higher power for hundreds of years.

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

A modernist landscape of water and sci-fi concrete.

A hidden network of subterranean passageways lies tangled beneath Indianapolis' bustling City Market.

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.

The longest continuous lava tube in the continental U.S. offers 2.5 miles of dark explorations for the adventurous.

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

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

World-famous, Pink's still manages to keep its prized cult fetish status.

A hand-built folk art installation covered with messages of God's love.