Sorry meant to say that I also went to Cologne when I was in Aachen and that is a nice city. The only other time I've been to Germany was to Munich/Bavaria. That was fantastic but a car is probably a must to explore the countryside and see the castles etc. Wouldn't Berlin be a more interesting place to go to than Aachen? I found it pretty sedate when I was there about 15 yrs ago.
I went there for a few days when DH was presenting at a conference umpteen years ago and i remember it as a nice place (think it used to be a spa town as known as Bad Aachen). Think it is famous for its gingerbread. A couple of days would be enough time to spend there as I don't remember doing that much apart from wandering around and eating gingerbread.
Not sure Bonn would have much to offer but cologne is really fabulous. It really depends on how you are planning to get there and get around. Cologne has an airport with good cheap flights so that's a bonus.
My personal favourite German city for visits is Heidelberg. It really is truly beautiful and there is a lot to do and see.
Aachen is also nice though and if you can get out into the surrounding area then you will see some stunning scenery!
Not sure I can be much help but we were near Aachen at Easter with a 14 year old DD. However we also had a 9 year old in tow so needed to accommodate both and booked into a Landal park.
Embarrassingly we didn't see anything of Aachen itself other than the train station. We went from there to Cologne and visited the Cathedral and then caught the Shockoexpress to the Chocolate museum which was a good day out. We had family to catch up with so nothing else we did very relevant. DD loved Cologne.
Not sure Aachen would necessarily be my first choice for a first trip to Germany. Think I would rather do somewhere like Cologne, Bonn or Berlin but it does depend what you are looking for.
DS has just started learning German and very eager to go to Germany. I am keen to encourage him, and also Charlemagne is my hero so wondering about a few days in Aachen in the Oct half term? (Can't spend more time as have thesis to finish..) Any views on Aachen things to do for 13 year-old boy? TIA!