Amsterdam's former hotspot for public executions and dissections.

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

This gorgeous reading room houses the oldest and largest art history library in the Netherlands.

This beautiful 19th-century temple stands atop the ruins of its predecessor.

Golden cobblestones remember a time when this small alley was used to avoid having to give a Nazi salute.

The footprint of a frustrated devil in Munich's Cathedral.

According to legend a man pooped out the window of this tower to prove that it was straight.

Every hour the doors open to reenact the legend of the heroic mayor who saved his town by drinking a gallon of wine.

Horrifically creative torture devices and shame punishments line the walls of this chilling museum.

The house where the writer spent his formative years.

The Grand Lodge of Ireland is one of the oldest in the world, full of fantastical, elaborately themed rooms.

Experience what life was like in Ireland during the Viking and medieval ages.

The somber sculptures commemorating Irish Famine on the river Liffey in Dublin.

A beautiful Victorian statue shows France's enduring love of the rhinoceros.

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

This mysterious and unique painting is filled with symbolism.

Graffiti from the 16th and 17th centuries cover the walls of this part of the Tower of London.

This historic building displays the remains of a victim of the devastating 14th-century plague.

An architectural oddity hides in plain sight on this iconic London bridge.

These mysterious Viking chess pieces spent centuries hidden on a remote Scottish island.

This medieval church tower has maintained its clockworks since the 16th century.

An unusual ode to the late Irish playwright, complete with a squiggly bust and coffin-shaped bench.

A labyrinth hides in plain sight at each of the city's 270 Tube stations.

Tucked away in the Tower of London is the weapon once used to execute high-profile prisoners.