Hohenzollern Castle of Germany (德國霍亨索倫城堡)

High up on Mount Hohenzollern in the Swabian Alp, about 50 kilometers south of Stuttgart, is Hohenzollern Castle. This mighty fortress has been twice destroyed and twice rebuilt. The original castle was built in the 11th century for the Hohenzollern family, who eventually became German emperors. It was besieged in 1423 and rebuilt 40 years later so that the Catholic Hohenzollerns could have a refuge during wartime, such as during the Thirty Years' War. After the fighting died down, though, no one saw any use for it anymore, and the neglect caused the castle to fall into ruins. It wasn't rebuilt until 1850, when Crown-Prince (and later King) Frederick William IV of Prussia wanted a family memorial. As such, this gigantic piece of real estate never had any inhabitants, except for a brief period of tenancy when the last Prussian crown prince, William, stayed there with his wife from 1945 to 1951. Now the castle is a popular tourist attraction and houses many artifacts of Prussian history, as well as personal effects of the Hohenzollern family.