Macabre astrological automaton clock dating to the late 1400s.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

According to the Guanches, the aboriginal people of the Canary Islands, the king of evil lives inside this volcano.

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

Holy Grotto of Montserrat Monastery holds one of Europe's mysterious black Madonnas.

Mountain where Jesus was first tempted by the Devil.

An unusual stroll through gentlemen's erotica demonstrates that pornography is timeless.

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

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

Dublin's "Dead Zoo" serves as a window to Victorian museum design.

One of Ireland's most infamous prisons for rebels including men, women and children.

Monasteries on rock pillars, once accessible only by frayed ropes.

This bridge was constructed from the rubble of the infamous Bastille.

An old slave lookout in Cuba's historic sugar cane fields.

No one knows the meaning behind this giant sculpture of a nude woman with a fork riding a rooster in Havana.

Neo-cave art on the macro scale.

After the Cuban Revolution, the famous rum company had to leave their swanky headquarters behind.

Once a favorite playground for the world's most illustrious guests, Hotel Nacional's secret weapons and bunkers reveal a more menacing side to its golden history.

In terms of history and architecture, this is one of the most remarkable cemeteries in the world.

A focal point of the Cuban government, this city square features one of the most iconic images in the country.

The second-longest pier in the U.K. stretches a whole kilometer into the Irish Sea.

The tower was originally used as a chimney for the waste incinerator of St. John's Precinct and Market.