This Nazi-built amphitheater was constructed on a sacred mountain site used by various German cults.

Sitting in the basement of a castle, the largest wine barrel in the world is bigger than most apartments.

A preserved college lock-up that recalls a clubhouse approach to discipline.

A collection of artworks exclusively created by the mentally ill that was almost burned by Nazi culture police.

Fantastic views and thousands of love locks.

Carved fountains poignantly placed in parks and in front of special monuments.

On October 17, 1814, a 15-ft. wave of beer ran rampant through the streets of London.

The signs of a long buried road can still be found hidden beneath a London sewer grate.

On a wall in linear London, a plaque hangs at the high water mark of one of the worst floods in fictional Kcymaerxthaereal times.

A 142-foot-tall Q-tip on Bristol's skyline.

The mummified heart of a saint lives on in this church—after a brief hiatus when it was stolen.

Amidst the bustling streets of Dublin, there is a hushed garden that is dedicated to "All those who gave their lives in the cause of Irish Freedom."

A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

This natural history collection contains the bones of a circus elephant that seem to be chasing a whale skeleton.

A miniature Italianate fantasy village on the coast of Wales and the set of ITC classic "The Prisoner."

A subterranean playground in an abandoned slate mine.

Europe's largest prehistoric mound – burial site of a legendary king?

The site of London’s first coffee house has been serving refreshments of one kind or another for 360 years.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the first ‘Harry Potter’ film.

The Bristol Camera Obscura housed in an ancient windmill.

The ruins of an 800-year-old monastery boasts the tallest round tower in Ireland.

A harem-inspired Moorish fantasy design in a Victorian-era Welsh castle.

Every May, townspeople welcome summer with a bizarre pagan parade led by a man wrapped in garlands.