A 16th-century horror show built in a lovely Italian garden.

For two weeks every June, fireflies in the Smoky Mountains perform an astonishing light show.

This faux-seedy Japanese arcade is made up to look like a maze of alleys straight out of a cyberpunk dystopia.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

Dramatic river bend surrounds a natural red-rocked pedestal.

The ghost town left by the worst nuclear disaster of all time is being taken over by nature and urban explorers.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

Rippling sand dunes frozen in the Arizona rock.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

An artsy hidden staircase leads to breathtaking views of San Francisco.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

A huge musical instrument played by the ocean.

During prohibition, corrupt city officials ran drinking dens under the streets of Downtown Los Angeles.

The eerie ruins of an isolated abandoned town nicknamed "the Widowmaker" for its deadly gold mine.

Folklore says this medieval fortress was plopped atop a portal to hell to trap the demons below.

A spooky juxtaposition of caves and graves gives this legend-filled cemetery a particularly haunting vibe.

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

Red frames showcase remnants of one of New York's original subway stations.

This study room in the New York Public Library saw the creation of one of contemporary America's greatest traitors.

Possible relics of the ancient Roman city are hidden in this restaurant's façade.

This abandoned caretaker's apartment is one of 13 left in the New York Public Library system.

Hidden in one of New York's oldest subway stations is the final remnant of the site of the bizarre Shakespeare Riots.

A Manhattan courthouse hides a small but scathing memorial to Holocaust injustice.