A four story, football field-sized, nine-grotto creation made of shells, minerals, and rare stones.

A 300-yard long natural tunnel runs through a ridge deep in the Appalachian Mountains.

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

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

An arsenic-filled pool in the Grand Canyon takes on the appearance of a giant, overflowing pumpkin.

This massive store is home to an eccentric collection of vintage, retro, and peculiar goods.

A meditative space out of a fantasy story.

This Big Sur waterfall drops 80 feet directly into the Pacific Ocean, and inspired the hillside house up top.

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

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

A house carved into a rock in the 1940s.

A clear blue swimming hole with hidden caves, still unexplored.

This former lieutenant governor's home is brimming with curiosities.

Less a museum than a bizarre fantasy world created by artists and engineers.

This futuristically sylvan church is a glass-enclosed marvel of modern architecture.

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

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

Tour the sci-fi-esque reality of governmental disease management.

A masterpiece of LGBT art has been restored in what may now be the most valuable restroom in America.

A shop full of natural curiosities, carnivorous plants, and costumed taxidermied mice.

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

Rustic natural hot springs in the deciduous rain forest.

A mysterious castle built as a monument to lost love.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."