A striking memorial recalls thousands of Bolognese men and women killed fighting fascists in World War II.

Legend has it this fountain built to symbolize the Pope’s power hides a strange secret concerning Neptune's manliness.

Inside this McDonald's you can dine on your Big Mac and fries next to a 2,500-year-old Roman wall.

An ancient well nestled at the foot of Glastonbury Tor, shrouded in Arthurian legend and revered for its purported healing waters.

The tallest hotel in Europe.

Backwards hour and minute hands and a timing mechanism that fluctuates with the temperature led to this clock tower's local nickname.

The Polish capital has had a deep connection to its guardian mermaid for almost a millennium now.

This biographical museum honors the groundbreaking scientist at her birthplace in Warsaw.

Where commuters walk through remnants of an ancient Greek necropolis.

An ancient octagonal weather station named for the eight Greek gods of wind.

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

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

The crypt of the imposing Stephensdom holds royal intestines and thousands of skeletons.

The beautiful baroque library of the Hapsburg empire.

An 11th-century runestone decorates the halls of Terminal 2 of this Scandinavian travel hub.

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.

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

A rare memorial paying homage to an altruistic woman from the 19th-century.

The most loyal of little dogs, or a Victorian era publicity stunt?

This otherwise ordinary close on the Royal Mile constituted the end of the world for Edinburgh’s poorest residents.

This beautiful deer park was built so King Charles I and his court could go hunting while escaping a deadly plague outbreak.

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

Two plaques commemorate the site of Shakespeare's first theatre.

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