Brass plaques embedded in pavement preserve the memories of those who lost their lives at the hands of Nazis during World War II.

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

This museum housed in a former brothel explores the past and present of sex work in Amsterdam.

In 1988, jazz legend Chet Baker fell to his death from a window of this hotel facing Amsterdam Centraal.

This historic Amsterdam bar used to accept sailor's monkeys as payment.

The attic of a four-century-old canal house hides a clandestine church.

Widely advertised as Amsterdam’s narrowest street, this passage was once a highlight of the Red Light District before its windows closed.

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

A Dutch passageway's artistic, aquatic-themed makeover pays tribute to the capital city's famed waterways.

Milan's duomo is covered in beautiful carving including a curious "dinosaur-like" beast.

An extraordinary collection of 18th century anatomical waxworks.

"Unity, Creativity, Beauty."

This grisly effigy displays an early Christian martyr who was skinned alive and beheaded.

This cathedral hides a sculpted dog that determines your fate and an unexploded shell from World War II.

The "Mona Lisa" of funerary art.

Every day is like Christmas on this street where the traditional Neapolitan nativity scene comes to life.

Pilgrimage site for star-crossed lovers.

Massive puppet-automaton machines created by French artist collective Machines de l’Ile.

The celebrated eyesore created by starry-eyed sweethearts.

The oldest continuously operating mint in the world that has been making coins since the 9th-century.

If you look closely at the oldest bridge in Paris, you might notice hundreds of ugly faces leering from its sides.

During the summer months, giant teddy bears take over Paris near Les Gobelins metro station.

What looks like a normal building is really a hollow facade hiding a subway vent.

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