The Old Lahn Bridge is one of the oldest standing stone bridges in Hesse — its core arches date to the 13th century and have carried traffic ever since, with rebuildings after war damage and the usual repairs. The seven arches span the Lahn at the narrowest point below the cathedral.
The view from the bridge is the classic Wetzlar photograph: the river curving around the Lahninsel, the cathedral towers above the rooftops, and the old fishermen's houses leaning toward the water. Walk across in either direction and double back along the riverside path — half an hour at most, and the easiest way to grasp the layout of the medieval city.