The remains of 40,000 humans, meticulously stacked in a tiny churchyard shed.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

Hundreds of prehistoric stones, arranged in perfect lines in a French field.

This French ghost town from World War II has been left as a memorial to German atrocities during World War II.

A well-preserved medieval village nested on a rocky outcrop and surrounded by a network of cliffs, natural bridges and canyons.

Historic medieval fortified city in southwest France.

Every half hour, the flow of this unusual spring cycles between a rush of water and barely a trickle.

This French castle is said to have once held the Holy Grail but is now a gorgeous mountaintop ruin.

Small French town or alien garage?

Bordered by forest on three sides and the ocean on the other, the Great Dune of Pilat is the highest sand dune in Europe.

Winston Churchill painted this lake during his stay Woolsack Castle in the Landes forest.

This narrow path was cut right into a French mountainside to feed the country's early naval expansion.

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

France's most famous cemetery, with some of its most curious tombs.

A red-brick beacon stands against the tempestuous Atlantic, on the windiest site in the United Kingdom.

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

A statue in Budapest's Liberty Square honors the former U.S. president's efforts to end the Cold War.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

One of the largest busts in the world celebrates the German city's erstwhile namesake.

This strategic isle was once swapped between empires and almost entirely destroyed in a bomb explosion.

A stonemason's hilarious revenge came in the form of this peculiarly positioned gargoyle.

The small alleys in Lübeck's Old Town are a result of medieval urban sprawl.

The birthplace of Karl Marx is now a museum dedicated to the communist revolutionary's life and work.