This one-time health resort was used by aristocrats around the world.

A random tree outside a Budapest hotel has become a DIY shrine to the late singer.

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

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

The final resting place for the remains of 143 Habsburg royalty.

Built to give thanks for the passing of a plague epidemic, this cathedral is a one-of-a-kind architectural hybrid.

Baroque celebration of the end of the Great Plague of Vienna.

A turn of the century building boasting some of the most beautiful art nouveau architecture in Prague.

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

This Prague museum collects brutalist relics and memories from the country's former Soviet rule.

Two stunning 17th-century libraries and a cabinet of curiosities.

Macabre astrological automaton clock dating to the late 1400s.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

A monument to the man who almost killed Hitler.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

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.

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

Real bones which are said to have belonged to a Polish dragon.

An underground city of salt.

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

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

This Wall Street bar was once a hub of revolutionary activity where Washington famously bid farewell to his troops.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.