LUDWIGSHAFEN, GERMANY. Ludwigshafen is your gateway to a choice of four excursions. Visit Heidelberg, the perfectly preserved medieval city nestled in the Neckar River Valley along Germany’s Castle Road. Discover the iconic red sandstone Heidelberg Castle and Great Vat, an 18th-century, 49,000-gallon wine cask. For a more active adventure while in Heidelberg, join a guided hike up the Philosopher’s Path, aptly named during the Romantic Period, and enjoy panoramic views of the city. Alternatively, you can visit one of Germany’s oldest cities, Speyer, known for the largest Romanesque cathedral in Europe—a UNESCO World Heritage Site—and the medieval Old Gate, Altpörtel. Or pedal along the river Neckar to the picturesque medieval city center of Ladenburg and enjoy some free time to explore the shops. (B,L,D)