The vast, legendary catacombs hold secrets much stranger than stacked bones.

An overgrown and abandoned tuberculosis ward resides in the midst of a quaint modern neighborhood.

This modest post office sits on the site of H.H. Holmes' famous murder castle.

A beach made of semi-precious green sand on the Big Island of Hawai'i.

Much of what constituted mid-century Liverpool now litters a beach outside of town.

Near-constant high winds deform the trees on Spruce Knob, the highest point in West Virginia.

This sprawling mini-golf empire is an impressive testament to a disappearing attraction.

A dilapidated psychiatric facility on the outskirts of Milan where electroconvulsive therapy was developed and Napoleon once lived.

The oldest of Venice's plague quarantine stations, designed to keep the medieval city safe from disease.

A small island less than half a mile from Venice is a forbidden island with a dark and twisted past.

This real life asylum of horrors is now an abandoned ruin that hides the unbreakable code to one patient's insanity.

This former abandoned hospital, a complex of stunning 19th century buildings, once housed 2,000 psychiatric patients.

Venice's "Island of the Mad."

The decaying ruins of Wales' first asylum for the mentally ill.

This abandoned asylum in Wales might look haunted, but it's still beautiful.

What was once the largest mine in North America has left behind a hollow hill filled with bright blue waters.

This crumbling industrial fortress has attracted daredevils, filmmakers, and historians.

When World War II came to Canada, Fort Péninsule was part of the first line of defense for Allied shipping convoys.

Dedicated to the people of Indian Head, Saskatchewan.

Concrete pillars provide a beautiful canvas for Quebec City's graffiti artists.

A swirling spectrum of stained glass dazzles visitors who enter this subway station.

A roadside attraction fit for a giant.

A former electric substation that was converted into a magnificent mansion.

The oldest operating steam locomotive in Canada runs along this heritage railway.