Ancient castle ruins in the midst of thick woodlands, quiet university towns, busy manufacturing centers -- you'll find all these in the countryside of southwestern Germany. The area extends along the Neckar River from Heidelberg past medieval towns and modern cities as far as Tübingen. The Neckar flows between the Black Forest and the Schwäbische Alb region. Although the river is open to commercial shipping vessels as far as Stuttgart, much of the valley has remained unspoiled. The castles that rise around every bend in the river were once home to the German royal families of Hohenstaufen and Hohenzollern. Today, castles and country palaces sometimes offer bed and board to travelers.