In the heart of the Ries crater rises the former Free Imperial City of Nördlingen . Situated directly on the Romantic Road, it is encircled by Germany's only completely preserved and walkable city wall . The beautiful medieval town center entices visitors with old half-timbered houses, the picturesque tanners' quarter, a unique view from the top of the Daniel tower (the tower of St. George's Church), and other highlights around the market square. Nördlingen is also the ideal place for a lunch break on the Danube Geological Discovery Tour.