Some buildings impress you with height, others with mass. Speyer Cathedral does it with both, rising from the left bank of the Rhine with six towers and a long, rhythmic nave of red sandstone. It was begun around 1030 by the emperor Conrad II, the first of the Salian dynasty, and is generally considered the largest surviving Romanesque church in the world. Its crypt, a forest of sturdy columns and striped arches, holds the tombs of several emperors and kings, which tells you how central this town once was to the Holy Roman Empire.
Speyer itself is a lively, walkable city of around fifty thousand people. The broad Maximilianstraße runs from the cathedral to the old gate tower, lined with cafés, ice cream parlours and stalls selling the city's giant pretzels. Speyer hosted many imperial diets, including the 1529 assembly where Lutheran princes issued the protest that gave Protestants their name. The Jewish community of medieval Speyer was one of the most important in Europe, and the remains of its synagogue and ritual bath, the mikveh, are part of a separate World Heritage listing.
For riders, the Technik Museum Speyer is a magnet, with aircraft, a space shuttle prototype, locomotives and a respectable collection of motorcycles. The riding in the area is flat on the Rhine plain, with river-meadow lanes and the occasional small car ferry across the Rhine, but the Palatinate Forest begins just west of Neustadt and offers fine winding roads through sandstone hills. The German Wine Route along the foot of those hills is pretty but slow, packed with villages and wine festivals in summer and autumn.
Speyer is an easy town for a break: pumps on the main roads, food on every corner. Park near the cathedral on the edge of the old town; the centre is compact and pleasant on foot. In the Palatinate, try Saumagen, a stuffed pork stomach that sounds worse than it tastes, or simply sit in the cathedral garden by the old stone basin, the Domnapf, which by tradition was filled with wine for the people whenever a new bishop took office.