What's there to see in Heidelberg, Germany?

Hi. We are planning to drive around Germany in a hired car and right now I am exploring possible itineraries. I saw on the net that Heidelberg is quite a popular destination for tourists. Should we pass through there? Is there anything to see here? Have you been and what did you think? I would appreciate your comments.

Some say that Heidelberg is the real Germany. It is a wonderful, charming town. The air is very healthy here and it is full of mountains and flowers. They say that it is one of the cradles of civilisation too, as some of the oldest human remains were found here. Dont miss out on Heidelberg. The whole family will be able to really relax and be themselves here.