Human-made caves excavated to hide a secret society of wealthy pagans.

This churchyard arbor is surrounded by hundreds of gravestones placed there by author Thomas Hardy.

Monument to a brutal, ineffectual US bombing campaign and a sobering reminder of the human cost of the Vietnam War.

Believe It or Not, Ripley once called this chiseled mountainside “New York’s Mount Rushmore”.

Don't be fooled by this fake medieval facade even if it is almost 300 years old.

Abstract dinosaur models in London.

The remains of Crystal Palace Great Exhibition of 1851.

Remnants of a Victorian garden feature sitting in public woodland.

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

Scattered throughout London are ancient remnants of the city's former bounding wall.

This one has sailed five times as far as Sir Francis Drake's famous ship.

Pop culture has helped to keep this iconic British building from being destroyed.

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

A 2000-year-old Roman amphitheater lies just below Guildhall Yard.

Since 1874, this macabre collection has developed into a museum devoted to Scotland Yard's mementos of dastardly deeds.

This religious museum resides in a church crypt next to the founder's house.

An unusual round church in London with a Templar past.

The television series' iconic giant foot was borrowed from this classical painting.

The ruins of an Estonian prison are drowning in the quarry lake where the convicts were once forced to work.

The first spinning jail built in the United States is the only one that still turns.

The world's only three-story rotary jail is now a museum to a bizarre trend in prison design.

Deep under Manhattan is the largest construction project in city history. So far, the project has taken the lives of 23 workers, or "a man a mile."

An odd, ancient window that may have once been part of a brutal prison is embedded in the side of New York's Police Plaza.

More than half of this Indian palace is drowned but it looks all the more spectacular for it.