Cold war icon and onetime "hole" in the iron curtain.

The site of the famous Nazi book burning campaign of 1933 remembers its "Night of Shame".

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

Started as a kitchen garden, now the second largest botanical garden in the world.

Possibly the world's largest hourglass only needs to be reset every New Year's Eve.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

The red letters in the literary pavement leading to the library form a mysterious code.

Mysteriously stacked storefront paths give this medieval British town an iconic style like none other.

Created as a punny statement about genetic engineering this monstrous hybrid statue has become a beloved icon.

A set of 27 bamboo tubes creates an eerie soundscape that changes with the wind.

Rich with fauna and flora, nature-lovers can walk across the sea at this UNESCO World Heritage spot.

Incredible labyrinth of man made caves.

These slanted cubic abodes are a creative if odd solution to a zoning pickle.

Unsurprisingly, Holland is home to one of the most magnificent flower gardens in the world.

The world's most elegant power lines.

Spain's stunning solar energy plant.

A merchant court dedicated to the fictitious King Arthur is heavily adorned with bizarre Renaissance art.

Its town washed away centuries ago, this lonely tower by the sea tells the tale of a mermaid and a curse.

The 20-mile causeway that separates the Netherlands from the sea.

A maze of crosses marks the jumbled divide between the Netherlands and Belgium.

The Netherlands' first car tunnel has an unusually rectangular shape.

There was a top secret plan during World War II to seal a group of soldiers inside the rock.