Karlsruhe has a very nice downtown area with a castle and a number of historic sites nearby.
Tourist attractions in the close surrounding include the cities of Heidelberg and Baden-Baden, and the Black Forest and the Alsace as recreational areas, for hiking and other outdoor activities. Also, the area of Karlsruhe is famous for its vines and cuisine.
For more information please visit: Karlsruher Tourismusportal
For information about guided tours please visit: Excursion