St. Mary's Asylum was isolated and abandoned before being converted into a Bed and Breakfast.

What was once one of the country's largest confectionary plants is now an abandoned ruin, but is still pretty sweet.

An abandoned village that doubled as "The Hunger Games"' post-apocalyptic wasteland is up for grabs.

A recently abandoned psych ward at the end of Sanatorium Road.

A once-booming Mississippi River town with a history of racial violence is now eerie and mostly abandoned.

Oh, just a motel on the edge of the desert decorated with thousands of clowns conveniently located next to an abandoned graveyard.

A sculpture made of 10 Cadillacs as a monument to the "Golden Age" of the American automobile.

A mysterious castle built as a monument to lost love.

European castle ruins in an American state park are actually the product of death and grief.

One of the most scenic stretches of road in America winds between some of the country's oldest trees.

A whimsical village of unique treehouses resides in a Washington forest.

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

An acoustic anomaly with a mysterious cause.

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

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

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.

Towering basalt columns, a creation of fire and ice.

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

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

A self-built castle made by a mysterious man.

An abandoned facility that has become a place of ritualistic satanic worship, or so rumor has it.

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

A beautiful geyser under environmental threat.