I'm driving around Switzerland, Austria, and Czech Republic at the end of June, and will be driving through Germany to get to Amsterdam where I fly out from. I have a few extra days that I would like to spend somewhere in Germany, but I can only pick one city. I enjoy historical/beautiful places that I can easily get around in. I don't have any desire to see Berlin (at least this time around), but that still leaves a lot of options. What city would be the best option for this type of journey?