These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.

A tiny church on a man-made island in the Adriatic.

The most visited, and possibly most controversial, museum in Germany.

A memorial in the Tiergarten is a reminder of the suffering inflicted on homosexuals by the Nazi regime.

An imperial church bombed to ruins during WWII now stands as a jagged memorial.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

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

An eerie, derelict amusement park in Berlin.

A creepy statue of a hooded ghost hauls itself up from the water in a historic Lithuanian city.

Lithuania's outdoor sculpture trail of wooden folk art.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

This historic covered bridge contains a series of macabre paintings that communicate one thing: everyone dies.

This is not only one of the oldest collections in Europe, but also possibly the most beautiful.

Inside this small chapel tucked away in the forest is one of the most well-preserved Danse Macabre frescos.

This military tunnel dates back to World War II and provides visitors with a little wartime adrenaline.

One of the best-preserved Roman amphitheaters is still used today, but for less brutal events.

Croatia's "hairy stone" fortress is one of the most well preserved Istrian castles.

Nibble as you learn about Slovenia's longstanding tradition of making beautiful honey cookies.

This massive subterranean fissure is known as the "underground Grand Canyon."

A stunning architectural yet functional feat, towering over Oslo.

A statue that would be at home in Rome can instead be found in the heart of Norway's oldest city.

The former home of Norway's greatest romantic composer.

This roadside attraction looks like a flying saucer parked atop the tundra.

A naturally occurring tunnel in this Nordic mountain makes it look like it's been shot.