Medieval Český Krumlov has a perfect little river snaking its way through the city center. In summer, people tube down it taking in the sights as they go (a joy I didn’t get to experience having visited in October and not personally being a polar bear plunge fan). The town has a lot of daytime tourists, but not many sleep over. Spending a night in the cobbled old town is definitely worth a relaxing evening when heading south from Prague or north from Vienna.