The current, modern city of Nuremberg has an amazing walled city in the middle of it. The old, medieval walls are protecting Nuremberg Castle. I was surprised to see how much of the walls were still intact, and the city takes great care to make sure that it stays this way. The whole system creates a big circle, so just pick a direction and start admiring a piece of history. There are tons of places to sit along the way if you get tired. You can even use the walls to get to different points of the current city. Definitely a unique and interesting feature that most cities do not have.