Photo: Wikimedia CommonsThe Eiserner Steg is the much-loved iron footbridge of Frankfurt, striding across the Main between the old town and the museum riverbank of Sachsenhausen since the nineteenth century. Draped in love-locks and offering a classic view of the skyline, it is one of the best free strolls in the city. Cross at dusk for the skyline reflected in the river, and follow the south bank to the run of museums along the Schaumainkai.