Walk inside a half mile long crevice right outside the town of Garmisch Partenkirchen.

Dine amidst exotic plants at this former royal greenhouse.

Baroque celebration of the end of the Great Plague of Vienna.

A castle from the Holy Roman Empire that hosts traveling youth... in its stables.

This ancient ruined monastery has been destroyed by fire so many times that it seems like God hates it.

This pink watchtower served as the seat of the Greek government after independence from the Turks.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

An ancient octagonal weather station named for the eight Greek gods of wind.

An ancient Greek monument and a Byzantine church coexist inside this cave.

Heralded as the world's first theater, these ruins are often overlooked as they reside in the shadows of the Acropolis.

Legend says this sacred tree was a gift from goddess Athena.

This church was constructed on the site where St. Philip the Apostle preached to the ancient Athenians.

Now harmless, this looming post struck fear into the heart of medieval troublemakers.

A musical instrument played by the sea.

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

This Nazi ruin was the site where Hitler was almost blown up by a suitcase bomb.

Some believe that the artist behind this whimsical statue inserted his own likeness as a way to discreetly flip the bird.

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

This 12th century, partially destroyed, abbey has had several owners and was seized during the French Revolution.

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

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

Ruins of a German castle on top of a towering stone pillar.

Horrifically creative torture devices and shame punishments line the walls of this chilling museum.

This Dresden church was purposely rebuilt Protestant after being demolished in World War II.