In former days Worms was an imperial residence on the banks of the Rhine. Today, the town extends along the river that irrigates the rich soil of the Palatinate Plain vineyards. The town is famous for the Diet of Worms, to which Luther was summoned in 1521 and before which he refused to retract his beliefs. As a result, he was banned to the outer reaches of the empire. We can still see many vestiges of the old city walls, particularly the Torturmplatz and the Karolingerstrasse.