Step into a world of stalagmites and stalactites at Atta Cave -- Germany's largest dripstone cave – and then visit medieval Greifenstein Castle! This day trip from Frankfurt includes a tour of the spectacular cave near Attendorn plus a walking tour of Greifenstein Castle. Marvel at the 12th-century ruins, and then visit the site's German Bell Museum, where more than 50 traditional German bells are displayed.Numbers are limited to 14 on this small-group tour, ensuring you'll see all the sights with personalized attention from a guide.