Fifteen Jodhpur queens left their handprints before going to their fiery death.

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.

The mortal remains of an estimated 70,000 people lie in the basement of a monastery in Lima, Peru.

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

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

A daring D-Day assault by U.S. Army Rangers is commemorated atop the high cliffs of this strategic point.

A memorial to the nearly 10,000 American soldiers laid to rest on the beaches of Normandy during WWII.

This castle-fortress is a living example of the transition from medieval defenses to modern fortifications.

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

This ancient theater was once the home of fierce gladiatorial battles.

A unique underground structure dating back to the 1st century BC.

This ancient Roman bridge and aqueduct still stands as a wonder of classical construction.

The world's most famous cheese caves.

This tri-part waterfall is a little bit of fairytale beauty in the heart of Luxembourg's Little Switzerland.

Oldest Museum of the Netherlands is a true cabinet of curiosities.

This still-celebrated home was a radical architectural experiment in 3D De Stijl.

Sacked by Vikings, blessed by William the Conqueror, dealt a fatal blow during the French Revolution—these ruins have seen it all.

Historic medieval fortified city in southwest France.

An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

Site of one of World War I's most horrific scenes.

This modern French ossuary contains the jumbled bones of 130,000 WWI soldiers.

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

Museum in a swimming pool where the water still flows.

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