Now a hotel, this former bank was the site of a robbery that spawned a psychological phenomenon.

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

The scars of a remarkably organized public protest to save 13 elm trees are still visible in this Stockholm park.

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

Several cannonballs of mysterious origins decorate two buildings in Stortoget's main square.

It is said that each of the white stones in the red facade of this medieval house represents the head of a murdered Swedish noble.

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

An ancient Viking runestone hidden in plain view in Stockholm's old town.

This centuries-old rooster survived a devastating fire.

A plaque marks the house in Stockholm where the French philosopher René Descartes lived up until his death.

A wooden street sign is the last remnant of this 400-year-old alleyway.

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

One of the world's first dedicated bank buildings in the world is now the oldest one.

A man has revenged his true love's betrayal through tears and stone genitalia.

The beautiful baroque library of the Hapsburg empire.

The former private quarters and office of Dr. Sigmund Freud now hosts a museum housing the works of the founding father of psychoanalysis.

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

Beautiful Austrian natural history museum with carved ceilings and row after row of ancient taxidermy.

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

Two stone columns flank the grand Venice square, but there were supposed to be three.

A new sculpture calls attention to climate change in the centuries-old city it threatens.

Model Trains and Much More in Hamburg.

Once the tallest building in the world, this abandoned church is now a monument to the destruction of WWII.

A museum dedicated to the history of a terrifying secret police is now held in their former headquarters.