This Soviet-era "closed town" was a top secret uranium producer often left off of maps.

The monster at the center of the Darwin Center Spirit Collection.

Hidden beneath the streets of London is a secret subway that only carried mail.

This beautiful example of Victorian engineering is the oldest water-balanced funicular anywhere in the world.

The nearly 200-year-old folly has a secret spiral staircase hidden in one of its pillars.

A statue honors the children who fought Nazis in Poland.

Late at night, the bust of the "Dracula" actor was snuck onto the facade of this Budapest castle.

This bronze statue was erected to honor a small Scottish town's beloved stray cat.

This century-old gargoyle has a mysterious history and may not actually be a rabbit.

Man-made caves excavated to hide a secret society of wealthy Pagans.

J.R.R Tolkien, C.S. Lewis, and other "Inklings" met at the Oxford pub to discuss the now legendary fantasy stories they were writing.

An Oxford museum where visitors can have tea with the Mad Hatter and climb through the wardrobe to a fantasy land.

Lyon, France is home to two remarkably preserved Roman theaters, one dating back to 15 BCE.

For hundreds of years, automatons moving to metallic music have been marking the passage of time.

Hundreds of hidden passageways weave through the old quarters of Lyon.

The broken skateboards that became a poignant memorial to a murdered skater.

Ship-sized kinetic sculptural fantasy.

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

A striking symbol of the Bulgarian capital.

A Bulgarian monument to Russia's role in World War II is constantly being painted in pop culture protest.

This luxury shopping lane has been protected by its own tiny police force for over a century.

Repository for more than 22 million pickled specimens.

70 million natural history specimens call this gargantuan museum home.

The final resting place to 300 Victorian-era pets hides inside the city park.