Spaced out along the western bank of the Rhine are three of Germany's most venerable cities - Mainz, Worms and Speyer - which have all, at one time or another, played a key role in the country's history, the most potent reminder of their status being the mighty Romanesque Dom dominating each city. The distinctive size and shape of these three cathedrals reflects the curious power-sharing arrangement between civil and ecclesiastical powers - with each having an unusually large say in the other's affairs - that sustained the fragile structure of the Holy Roman Empire for so long. Further west lie the wooded uplands of the Palatinate and Hunsrück . They are little-known regions, particularly to foreigners, and thus ideal places to get away from it all. However, public transport services are comparatively sparse, and they are best explored by car or bike.