Oh my god!
I have no idea. But Germany is a very camper friendly country, so there should be one around.
Maybe you find something on heidelberg.de?
Best,
Jakob
P.S.: Have a nice stay there.

Sorry – I was there on a conference visit and my accommodation was provided. I don’t know what the accommodation is like. Hope you enjoy your visit – it’s a beautiful city.

There are camp sites, but you just sort of happen-upon them as you’re driving down the autobahn. It’s pretty over here so you might find quite a few places…but never been to one myself.

Well, the one closest to the city (5 min from downtown) is here: http://www.camping-heidelberg.de/english.php