A museum dedicated to a secret military hospital hidden beneath a castle in Budapest.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

This colorful statue welcomes visitors to a Barcelona park.

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

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

An early 20th-century bullring converted into a modern shopping center.

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

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

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.

Mountain where Jesus was first tempted by the Devil.

This cemetery features modernist statues as strange as its name.

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

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.

A public urinal so pretty, it was declared a national monument.

One of Amsterdam's narrowest houses is located right across the canal from its widest.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

First founded in 1472, this is the oldest bank in the world. Its history may explain why we call financial institutions "banks."

Inside this park resides a giant clock tower and ancient sundial that overlook the town below.

This medieval church in Rome was almost destroyed following a terrorist attack in 1993.

This 1st-century CE Roman bath sits under a carpark.

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

A medieval, mosaic-lined baptistry built by a heretical Christian sect.

Psychoanalyst Carl Jung reported a paranormal experience after visiting this mosaic-lined Roman baptistry.