The Marktplatz is the heart of the old town: a steeply sloping cobbled square dominated by the painted Renaissance facade of the 15th-century Rathaus (town hall). The square is ringed by perfectly maintained half-timbered houses, most of them now cafes, ice-cream shops and student haunts. The Neptune fountain in the centre dates from 1617 and is a long-standing target of student pranks.
A market is held here every Monday, Wednesday and Friday morning, with local farmers selling vegetables, bread and cheese. Outside market days, the square is at its best in the late afternoon, when the sun catches the painted facade and the cafes fill with students arguing over coffee.