Stone Bridge and medieval Regensburg

Built in about eleven years, probably between 1135 and 1146, Regensburg's sixteen-arched Stone Bridge was for centuries the only bridge across the Danube between Ulm and Vienna, and Louis VII of France led his crusaders over it in 1147. Its tolls and the river trade made Regensburg one of Germany's richest towns, whose merchants built the tower houses still standing in the old town.