A prehistoric rock shelter that's literally in someone's backyard.

Western New York's largest independent bookstore doubles as a historical repository of all things Niagara Falls.

An underwater city for the dead.

The oldest surviving bridge in New York City, which reopened to pedestrians in 2015.

In the middle of an extremely unforgiving and desolate high desert is the most secret military facility in the world.

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

An abandoned castle owned and ignored by Masons carries a cursed history.

A museum befitting the city responsible for supplying the majority of the world's LSD.

Become a prohibition rebel.

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

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

This abandoned asylum was once a state of the art facility before devolving into one of the most deadly mental institutions in American history.

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

A New York garbage depot holds a secret collection of weird and wonderful refuse.

Possibly the most beautiful carillon in the world, set atop Iron Mountain in Florida.

This little museum is built on a theater that was once a wildly elaborate speakeasy.

This abandoned amusement park was built on a site with a dark history.

Hollywood's most famous landmark, the "temporary" sign that has stood for decades longer than intended.

Get lost in this haunting fairytale art walk through a man-made eucalyptus grove.

Its buzzing collection honors vibrator history.

Read a book next to a Midtown waterfall.

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

This morbid, delightful curiosity shop offers everything from animal bones to human teeth.

This strange seaside tower got its name from a wealthy eccentric who would hide coins among its stones.