An eerie, derelict amusement park in Berlin.

A Turkish ghost town abandoned in a population exchange with Greece.

The ruins of an abandoned crematorium haunt an eerie deserted German cemetery.

St. Mary's Asylum was isolated and abandoned before being converted into a Bed and Breakfast.

The construction of a new church near Venosa was started in the 11th century, but never finished.

Old neon signs from the City of Brotherly Love provide a snapshot of the city’s evolution.

An indoor miniature village and labor of love for Laurence Geiringer, a model railroad enthusiast.

This recreation of a 19th-century dime museum is full of oddities.

An incarceration museum on the spot of possibly the oldest prison in England.

The anatomical-pathological collection of a man who changed surgery.

A historic London pub with prison cells in the cellar and a "spy room" on the second floor.

A hands-off space for graffiti artists to hone and display their skills.

The hidden "ballroom" under a mansion lake was built by a criminal who ate a cyanide pill during his trial.

A vast overgrown cemetery, once known as one of London's "Magnificent Seven."

An unusual round church in London with a Templar past.

A special shop catering to the needs of things that go bump in the night, and also helps kids become writers.

Famously misunderstood wonder of the ancient world

Catacombs turned marketplace.

The world's largest collection of witchcraft regalia.

The world's first underground farm is in a World War II bomb shelter beneath the streets of London.

A 1,215-foot tunnel transports pedestrians beneath the River Thames.

The quaint little store that is said to have inspired a famous Dickens novel was only given its name after the book was released.

One part local history, 99 parts gruesome haunted house.

A subterranean ice warehouse that has lain hidden beneath central London for over a century is now open to the public.