Hamburgers are intensely proud of their tunnel beneath the river.

The world's first and only three-segment bascule bridge folds up into the shape of a capital "N" to let boat traffic through.

Ample proof that watery ends make for well-preserved, millenia-old mummies.

The Suurhusen church tower in Germany leans over farther than the famous Leaning Tower of Pisa.

This beautifully designed star-shaped fort was the premier defense system of the late 1500s.

A former ironworks that was the first UNESCO industrial site.

A copy of the Statue of Liberty greets visitors to the birthplace of Auguste Bartholdi.

The two massive guns that defended Cartagena Bay.

A fountain standing as a testament to a doomed alliance.

A marvel of Byzantine engineering under the streets of Istanbul.

Once the largest rope factory in Greece, this abandoned plant now stands like a ghost of industry past.

Thousands of rusting train cars have been slowly falling apart on the edge of Greece's second largest city.

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

A musical instrument played by the sea.

This unique structure allowed boats to bypass underwater mine barriers in the channel to enter the harbor.

Longest fortress system anywhere in Europe.

The now-overgrown beach resort was once frequented by Yugoslav military elite.

This abandoned prison was so notorious that its name has become a metaphor throughout Albania.

An Albanian monument to the Communism that nearly crushed the country is now a crumbling wreck.

One of 200 religious buildings recognized as a “culture monument.” 

A medieval bridge stretches over a sulfur-rich river that leads to year-round natural hot springs.

This ominous Albanian fortress houses tanks and downed planes as a reminder of their victories over Western imperialism.

A naturally beautiful, seemingly bottomless deep blue spring.

A scenic UNESCO site that doubles as a habitat for various forms of wildlife.