The first statue to be added to Saint Peter's Square in over 350 years is an ode to migrants and refugees around the world.

What appears to be an ancient Roman temple is actually a Catholic church.

Go inside to really appreciate this 500-year-old technological masterpiece.

In the past, Renaissance sex workers were encouraged to entice customers on this bridge.

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

Macabre astrological automaton clock dating to the late 1400s.

The slender brass strip in Prague's Old Town Square was used to tell time from 1652 to 1918.

What looks like a suicide in progress is actually a statue of Sigmund Freud.

A bust of Franz Kafka spins in pieces, reflecting the writer's inner torment.

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

The vast, legendary catacombs hold secrets much stranger than stacked bones.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

This demon atop the Notre-Dame de Paris looks utterly bored.

The oldest and smallest cemetery in Paris is only open to the public twice a year.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

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

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

This home designed for chocolate magnate Antoni Amatller is an exquisite treasure-box of Catalan Modernism.

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

A cemetery in Barcelona's Poblenou district is home to this touching funerary statue, which depicts death in the form of a winged skeleton.

Historic medieval fortified city in southwest France.

Now abandoned, the first public health hospital in the U.S. saw more than one million immigrants from around the world.

Lady Liberty's first beacon of enlightenment is now displayed in a museum near the statue.