I love to travel and discovered airbnb 5 years ago, and had really good experiences meeting interesting and open-minded people and being welcomed in an new place. It is such a great idea !!!
The room is near the center, near museums or the castle you can visit, shopping, big park for relaxing or making sports, market, supermarket , all you need is very near. I can offer you individual tours in and around Karlsruhe, just ask.