This spectacular track has run continuously since 1882.

The lush coastal city of Astoria is riddled with forgotten secret sidewalks.

A sculptor's dream castle turned fantastical ruin.

Behind the pink curtain, Au Bonheur du Jour, an art gallery of erotic archives.

A modern mechanical planetary system, part of a 10,000 year clock.

One of the largest-ever mental hospitals now sits abandoned, surrounded by 25,000 unmarked graves.

An extraordinary mixture of natural beauty and man-made phenomena.

Visit this playground of waterfalls, caves and sinkholes.

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

These beautiful ruins deep in the Pennsylvania woods are thought to have been a ski lodge or a speakeasy, but no one really knows.

The best Tiki bar in Las Vegas.

This home is decked out like a psychedelic explosion of colors and bowling balls.

Sail through this subterranean show cave that is home to a legend that would go on to name nearly everything around it.

This small-town Connecticut restaurant gives each diner a free book from its vast library.

The tea room that pushed the boundaries of adorable straight into...we can't find the words.

This lake in the Cascades lives up to its name, disappearing down a hole every spring.

Found art has transformed this Pittsburgh neighborhood into a psychedelic dream.

Enormous piles of historically significant stones, dumped by Congress in a forest, and abandoned for 60 years.

The one-time watch house for incoming ships at the Golden Gate now stands abandoned and hidden in trees.

A morbid secret lies hidden within the beautiful walls of the Boston Athenaeum.

An abandoned stretch of highway, deteriorating next to the operational one.

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

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

Better known as the "Body Farm," this unique research facility has been studying how human bodies break down since the 1980s.