Steglitz-Zehlendorf is home to Glienicke Palace, so why not stop by during your stay in Berlin. It's also full of great shops and cafes, so you can spend the afternoon having a wander. Berlin has other landmarks you might want to visit such as Brandenburg Gate.
Park Babelsberg is worth a pic or two when discovering Babelsberg. It's also full of great shops and cafes, so you can spend the afternoon having a wander.