Perhaps the most spectacular grotto along the Algarve coastline.

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

This abandoned coliseum was intended to be a grand Nazi rallying ground before it was halted at the end of the war.

The entrance to this Frankfurt subway station looks like an old tram car crashed into the concrete sidewalk.

Legendary site where an evil bishop was devoured by rodents.

A rare water-powered funicular, it uses a huge tank of water and gravity to do its work.

This tremendous timepiece was once the largest cuckoo clock in the world.

A famed artist's inspiring work of peace and tolerance.

While you wait to cross the street at a traffic light in Mainz, you might notice that the light is staring back at you.

Along the banks of the River Rhine lies a park that seems unassuming, but beneath the surface lies a long and fascinating history.