The world's longest known cave system.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

A museum dedicated to the alleged Roswell Incident.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

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

This Budapest bar allows drinkers to leave their mark on the walls, floor, and even ceiling.

A hotel and restaurant serving as the mecca of kitsch.

A beautiful geyser under environmental threat.

The first declared National Monument in the United States.

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

Carnivorous plants, medieval aphrodisiacs, and the largest original wood structure glass conservatory in the western hemisphere.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

The neon signs from Las Vegas' past find their final resting place at this unusual graveyard.

On the Oregon coast there is a natural hole that seems to be draining the sea.

The best Tiki bar in Las Vegas.

Dyed by iron oxide over centuries, these sandstone rocks rise thousands of feet into the sky.