When struck, the strange stones in this park ring like bells.

A plaque bearing the names of those who dedicated themselves to protecting Budapest's Jewish population during World War II.

The metal leaves on this tree are engraved with the names of Holocaust victims.

Museum dedicated to the terror regimes of Hungary.

This Budapest bar allows drinkers to leave their mark on the walls, floor, and even ceiling.

One of Rome's most picturesque and original bridges was also a popular choice for Grand Tour artists.

The remains of this 2nd-century Roman temple are incorporated into a modern building.

Stockholm's deepest subway station is also a stunning ecological wonder.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

This small museum nestled inside a souvenir shop is dedicated to Sweden's most well-known toy.

Stockholm's narrowest alley is barely over two feet wide.

Sweden's oldest street has not changed for nearly a millennium.