When a supermarket opened up shop within a medieval building it became protected by UNESCO on a technicality.

Formerly Yugoslavia's "forbidden island," this sleepy little city still holds the abandoned remains of military strongholds.

This easily overlooked memorial immortalizes the scars from the 1956 Hungarian Revolution.

Budapest's Communist-era statues, banished to the suburbs.

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.

This Budapest bar allows drinkers to leave their mark on the walls, floor, and even ceiling.

Visitors dating back to the 1600s carved their marks in the stones of the iconic tower.

Explore this medieval cathedral by trying to spot all the malevolent monsters hiding in its beautifully colored windows.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

The sweet story of how American cargo planes became known as "Candy Bombers" during the Berlin Blockade.

Tiny castle in the middle of the Rhine made you pay to pass.

The last bastion of Roman presence north of the Alps looms over a German town.

Berlin's old airport.

Soaring over 6,000 feet in the Bavarian Alps, this beer garden was once Hitler's 50th birthday present.

A small but immensely extravagant palace built by the "Night King."

A striking 12th-century-style castle built on the edge of a cliff.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

A sprawling Baroque park with 300-year-old hydro-pneumatic waterworks.

This medieval castle overlooking the Elzbach river looks just like it did hundreds of years ago.

The fairy tale castle of the "fairy-tale king."

This quaint Italian town keeps losing ground as the sides of its plateau slowly erode.

Five candy-colored villages on the Italian Riviera.