This bakery and museum offers tours of the tastes and mythology of Aachen's signature spice biscuit—just don't ask for the recipe.

The largest manmade caves in Europe now function as a motorbike club's headquarters.

Created as a "model concentration camp" to hide Nazi atrocities from the international community, this former camp-ghetto now holds a museum and memorial honoring the lives lost within.

Underneath the city that invented pilsners are a series of historic tunnels that have been storing beer for centuries.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

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

A cluster of headless, armless sculptures looms within a popular Polish park.

The silly symbol for an underground protest group is now scattered around the city.

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

An underground city of salt.

This monumental mural crafted nearly 40 years ago is still in perfect condition.

The world's largest boar is a huge steel titan found at a French rest stop.

This striking fort on the Maginot Line looks just as it did after being destroyed in the Fall of France.

This triumphal arch celebrating the Sun King's conquest of Lille is a masterpiece of military architecture.

A swath of France so devastated by war it is still forbidden to go there.

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

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

A colossal sculptural lion built by the same man who designed the Statue of Liberty.

This statue honors the thousands of Allied avians that served and died for France during World War I.

This memorial museum chronicles the apocalyptic destruction of the First World War.

The largest airborne operation in history was launched to capture this bridge.

This towering church is home to a world-famous organ and a treasure trove of medieval art.

These planks were originally installed to hold the dead.

The view that inspired the scenes of Dracula's first landing in England.