This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

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

The incorrupt tongue of the patron saint of lost things is venerated in this basilica.

It's good luck to be mocked by this monkey.

This medieval cathedral houses stained-glass windows featuring saints and pretzels.

This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

This historic covered bridge contains a series of macabre paintings that communicate one thing: everyone dies.

The martyr's wax-enhanced skeletal remains lie preserved in a glass case in the Santa Maria della Vittoria in Rome.

Things seem to roll, flow and run uphill on this short patch of road near Ariccia, Italy.

A church of bones, decorated with 40,000 human skeletons.

This early 19th-century graveyard is the final resting place of Vincent van Gogh's mother.

The burning of this 12th-century church kicked off a campaign of Norwegian Black Metal terror.

This spooky statue sits outside a famous Prague theater.

An eerie, existential museum dedicated to the author of "The Metamorphosis."

Macabre astrological automaton clock dating to the late 1400s.

An ever-growing literary collection housed in the apartment where the Russian author penned his final novel.

Explore this medieval cathedral by trying to spot all the malevolent monsters hiding in its beautifully colored windows.

These gutted monastery ruins still stand proudly in the middle of the Italian countryside.

People have been living in the cave houses on this Italian hillside since the Neolithic era.

Dug as a secret royal escape route, the tunnel became a wartime bomb shelter and dumping ground for vintage cars.

A hospital where antique dolls are given new life.

A labyrinth of ancient tunnels hidden below the city holds the ruins of 2,500 years of history.

This sword isn't waiting for a king to pull it out. It was placed there by a saint.

These "anatomical machines" are only one of the many strange items in this Italian crypt.