Visit the ancient, mysterious Roman catacombs ... in the Netherlands.

A pair of giant stone heads represent the ancient Roman saints beheaded here.

Thousands of flowers create enchanting pink tunnels over the city streets.

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

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

Red, white, and blue painted steps along with a Union Jack celebrate the outcome of Gibraltar's 1967 referendum.

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

Single runway interrupted by a busy road that cuts across its middle.

This hidden courtyard in the Andorran capital hosts a unique contemporary sculpture park.

This 15th century pharmacy displays a beautiful collection of ancient medicine jars.

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

A wunderkammer of mysterious objects and stories.

A narrow passage next to a cafe leads to a courtyard exploding with murals, tags, and paste-ups.

Tiny memorials honor individual victims of the Holocaust.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

This futuristic German television spire is actually the world's largest digital clock.

No need to strap in for a “ride” on this walkable roller coaster.

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

Constructed by forced laborers, this submarine pen is now a museum and war memorial.

There are two dozen tanks just sitting in an open field in Lower Saxony.

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

Wooden pathways run through this rocky landscape, which legend says was created when a dwarven king pulled down his own castle to stop raiding giants.

Between Neo-Pagans and Neo-Nazis, these strange rock formations have a curious cult following and a very strange history.

An electrical pylon under whose legs a normal gauge train can run.