After visiting the zoo, we headed down to Heidelberg (about 1 hour / 95 km south). There is a huge castle on the hillside which we took a tram up to visit. This was easily the largest castle we visited while in Germany. We didn't take the inside tour, but did see a huge vat that was used to make wine. We walked around the outside and saw the courtyards, and the grounds. This would be fun to see in the summer or fall. After visiting the castle, we decided to eat dinner at a cafe just outside the castle. It was good to warm up too! The wind was picking up and it was a bit chilly. One of their specials was Bratwurst and fries so that what most of us had. Pretty good too!