Thousands of graves lurk below the surface of this park.

The haunting cadaver tomb of a famous French poet, playwright, and filmmaker.

Colin Stokes "got a bit carried away" and built a castle that looks like something out of Tolkien.

After 400 years of being closed to the public, this monastery's underground tunnels and secret garden are now a museum.

Drink the 'Blood of Christ' in this Roman Catholic fever dream.

This unassuming stone is possibly the oldest Scottish memorial to the 13th-century knight.

When this former hospital pharmacy closed in 2013 it already looked like a museum, so they turned it into one.

This stunning iron gate designed by Modernist architect Antoni Gaudí is filled with mythic symbolism.

One of Antoni Gaudí’s earliest buildings, built between 1886 and 1890 for the industrialist Eusebi Güell.

Mountain where Jesus was first tempted by the Devil.

A beautiful but toxic fountain of mercury.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

The blood-soaked ruins of the castle where the murderous Blood Countess was walled in alive.

One of the oldest bridges in Norwich was used during the English witch trials and is said to be haunted.

One of the most well-preserved castles in Italy also contains a rare medieval example of a port fortification.

Eyam took steps to quarantine themselves and keep the plague from spreading.

Village situated on a narrow volcanic escarpment.

Remarkable medieval wall paintings decorate this 12th-century, dog-friendly church.

This "floating railway" is one of the world's oldest monorail systems.

Art historians have debated the identity of this medieval stone rider since the 19th century.

This macabre masterpiece of a mural is one of Francisco Goya's "Black Paintings."

The oldest restaurant in the world is this old-world Spanish eatery, still known for its suckling pig.

Abandoned for decades, trains still pass through the now-restored remains of one of Madrid's first metro stations.

Commonly acknowledged as the only public monument to the Devil himself.