On a slight hill at the northern edge of Nürnberg’s Old Town you can see the Emperor’s Castle (Kaiserburg), which has been there since at least the year 1050 and was the emperor’s residence — when he happened to be in town.
In those days the emperor (of the so-called ‘Holy Roman Empire’) didn’t have a capital city, but traveled around from one place to the next, and tried to have a castle of some sort available at each. A visit from the emperor was a mixed blessing, because the town and its people had to pay all the costs for the upkeep of him and his court. They were honored, presumably, to have him come and visit, but relieved when he moved on.
You can go up and walk around the castle grounds for free, or pay for a tour which also gets you into the museum and one of the towers.
The view from the castle is no doubt rather impressive if you don’t go up in a snowstorm like I did.
My photos in this post are from 2005. I revised the text in 2022.