If only the towering walls of Zahringen Castle could talk! But seeing they can't, inquire if tours are available to hear a couple of its intriguing tales instead.
When you've spent a bit of time at this fortified complex in Gundelfingen, why not make your way to Freiburg Main Cathedral, Muensterplatz, and University of Freiburg? They're not far from Zähringer Castle Ruins and also a hit with many travelers.