The romantic old city of Heidelberg and the famed spa town of Baden-Baden form the setting for this day trip across southeastern Germany. See the remains of a famous Renaissance castle, explore the enchanting woodland of the Black Forest, and get a firsthand look at the region's iconic sights. Your day starts with a ride south to Heidelberg, a picturesque city on the river Neckar. Tour the famous Heidelberg Castle for a look at the long courtyard, the mighty terrace, and one of the largest wine barrels in the world. Then, take a walk in the city's medieval town center to marvel at the Old Bridge, Karl's Gate, the Church of the Holy Spirit, and the House of the Knights, as well as the oldest university in Germany. In the afternoon, your tour continues to Baden-Baden, one of Europe's most beautiful health resorts and best-preserved spas. When you arrive, pay a visit to the elegant Kurhaus, where you can check out the immaculate gardens and parks around the stylish casino. Next, take a tour through the enchanting coniferous woods of the Black Forest and visit the Mummelsee, a glacial lake among the mountains that was left behind by the last Ice Age. Take some free time to relax amid this beautiful scenery and check out the locally crafted cuckoo clocks, which carry on a tradition that began here in the woods, before you set out for the return trip north to Frankfurt.