An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

Dummies recreate radiological discoveries from history.

A island reachable by a causeway at low tide is possibly one of the earliest Western European locations to be identified in text.

Sometimes an island, sometimes a rocky outcropping connected to the world by a tiny suspension bridge.

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

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

The taxidermy remains of the first mammal ever cloned from an adult cell are on display in Edinburgh.

Remnants of the 16th-century defensive wall still stand unassumingly within Edinburgh.

Protecting the dead from opportunistic body snatchers.

The 2,000-year-old beam is tucked within the pedestrian entrance to the old London Bridge.

The rose garden in Regent's Park where Pongo and Perdita met for the first time in Disney's "101 Dalmatians."

Ship-sized kinetic sculptural fantasy.

The final resting place to 300 Victorian-era pets hides inside the city park.

London's smallest police station is barely the size of a phone booth.

Catacombs turned marketplace.

Visit the ancient, mysterious Roman catacombs ... in the Netherlands.

The ruins of this Dutch castle sit atop a labyrinth of once-secret tunnels and passageways, dating back over 900 years.

This sprawling Belgian fort was once thought of as impenetrable but now it is simply an abandoned relic.

A Belgian self-built tower inspired by the Bible and ancient civilizations.

This centuries-old gothic monster has been converted into a sprawling, glossy bookstore.

This historical Netherlands fortress still bears the marks of its single siege.

Incredible labyrinth of man made caves.

A luxury hotel housed in a former 15th century Gothic church.