Hohenzollern Castle, Germany
This ancestral home to a line of German emperors would fit in with the fantastical fortresses imagined by J.R.R. Tolkien and George R.R. Martin. At 2,805 feet above sea level, Hohenzollern Castle really is a castle in the clouds. The current fortress is actually the third to be built on the site (the first was destroyed in battle and the second fell into disrepair). Today it is a popular tourist attraction.