The birthplace of the ferocious William the Conqueror, this castle is awash in medieval history.

The fierce beast perches atop a pedestal marking where the historic City of London gates once stood.

This crumbling medieval basilica once attracted pilgrims by the thousands to collect a miraculous dust that formed above the saint's tomb.

The mysterious megaliths have enchanted and intrigued visitors for thousands of years.

More stones than Stonehenge, all scattered within a windswept landscape sure to enchant 'Outlander' fans.

The world's only flying boat museum honors a small Irish village that sent 20th-century aviation to new heights.

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

Every hour the doors open to reenact the legend of the heroic mayor who saved his town by drinking a gallon of wine.

An effigy of a trapped paratrooper dangles from a Normandy church to commemorate one remarkable D-Day event.

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

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

A Victorian cemetery in the heart of Brooklyn remains a popular mecca of morbid curiosity.

Spain's unique Mosque-Cathedral has been a place of worship for both Muslims and Christians throughout its history.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

The comedy and tragedy of Oscar Wilde is preserved in a Dublin park, captured in a sculpture of colorful stone.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

In its day this historic fort held 100 cannons pointed in almost every direction to protect New York.

The true age of this ancient stone circle is unknown, but its stunning vista isn't in question.

This evocative New Jersey statue memoralizes the Polish victims of a Soviet massacre.

Possibly the oldest of Britain's ancient henges is also one of its most stark.

The smallest island in Manhattan is a manmade landfill dominated by a Buddhist peace arch.

Once described as the "Eagle's Nest," this ruined ancient city rests on a remote mountaintop.

Once America's longest-manned military fort, now an abandoned hulk.