The Cycladic architecture makes this Athens neighborhood feel like an island paradise hidden in the shadow of the Acropolis.

An ancient Greek monument and a Byzantine church coexist inside this cave.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

This Dresden church was purposely rebuilt Protestant after being demolished in World War II.

The largest treasure hoard in Europe is contained in a castle that was bombed out during World War II.

Europe's largest natural bridge has a 19th century royal chateau built into its side.

Ruins of a German castle on top of a towering stone pillar.

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

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

A 1,215-foot tunnel transports pedestrians beneath the River Thames.

19th-century scientists would make the pilgrimage here to verify the precision of their measuring sticks.

Thanks to modern navigational tools we now know that the true prime meridian runs through a park next door.

Local folklore claims that this wall was not built for defense, but to provide labor during a time of famine.

Increasingly decayed figures stand as a powerful reminder of the human costs of Czech Communism.

This walkway is so narrow it needs its own light to stop pedestrian traffic jams.

This automated sculpture of two men peeing will spell out text messages with their micturition.

An eerie, existential museum dedicated to the author of "The Metamorphosis."

A plaque marks the spot where the saint was shoved off the Charles Bridge and into the river.

A mocking tribute to the past and modern leadership of Prague.

Nine bronze hands protruding from a wall honor the student uprising that led to the fall of Czechoslovakia's Communist government.

The palace window through which Protestant nobles flung two Catholic regents, thus sparking the Thirty Years' War.

A bust of Franz Kafka spins in pieces, reflecting the writer's inner torment.

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

Throughout this shopping mall are medieval ruins that were discovered during the mall's construction.