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

A tribute to the Polish insurgents who fought in the failed attempt to end their city's Nazi occupation.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

An underground city of salt.

One of the cave cities of Crimea, built by the Goths in the sixth century.

The ancient ruins of an extinguished city amidst the bustle of a modern one.

This statue of the great Argentinian car driver is located near a famous curve of the Monaco Grand Prix.

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

One part local history, 99 parts gruesome haunted house.

The Liverpool street made famous by the Beatles is real.

The quiet field that inspired one of the most famous songs of all time.

Famously misunderstood wonder of the ancient world

Looking strangely like Rome's Colosseum, this unfinished tower has dominated the skyline for over 100 years.

This site contains overlapping ancient graveyards that existed about 1,000 years apart.

An ancient Scottish rock formation said to be the gravesite of a giant remains ensconced in legend and intrigue.

The bell that once tolled atop a lost Edinburgh gate now hangs for all to see.

Overlooked by many, the two famous Scottish warriors guard the main gate of Edinburgh Castle.

A sweet symbol marks the place where torturous executions were once carried out.

Elaborate tile work in this railway station tells the story of Portugal.

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.