The second-longest continuous wall on the planet protects a hidden secret in the deserts of India.

A walk through the historic city center, under the streets of Seattle.

The park preserves a single, rare species of carnivorous plant that spells doom for unsuspecting insects.

A particularly creepy abandoned hospital that sparks interest for lovers of the supernatural.

The world's largest man-made underground caverns offer unparalleled underwater wonders.

Rusted and decayed, this former mining site is a portal to the past.

This plot of old-growth forest is the largest surviving remnant of New York City's original woodland.

This elaborate Hindu temple is located in a Chicago suburb, but looks like it was transported directly from India.

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

Symbolic attempt to overcome the issues of life.

A forgotten Cold War relic hidden in the outskirts of a Wisconsin city.

A well-preserved Ancestral Puebloan ruin tucked beneath a desert cliff.

A haunted hot springs hotel that went from healing retreat to asylum before it was restored.

The abandoned zoo enclosures offer a perfect place to experience the other side of the bars.

One of the few surviving examples of the first lock and dam system built on the Ohio River.

This abandoned Olympic skiing facility still bears the scars of the Siege of Sarajevo.

This Central New York ghost town was once a prosperous railroad community.

The first "Hut" was actually a small brick building.

This abandoned bridge to nowhere stands secluded in the woods of a Cleveland suburb.

A Prada store in the West Texas desert that is never open for business.

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

This small record store was a favorite of Oasis's Noel and Liam Gallagher, who mentioned it in one of their early songs.

One man's ambition created this psychedelic log home.

A hulking remnant of Alaska's industrial gold mining boom in the 1920s.