The Place de la Réunion is the heart of Mulhouse. As far back as the Middle Ages it was a bustling centre of activity with regular markets, fairs and ceremonies. The square boasts a number of historic buildings such as the Hôtel de Ville (town hall), the Church of Saint Etienne, the Maison Mieg and the Pharmacie aux Lys…
The medieval town was originally surrounded by a city wall, but as the town developed during the 19th century the ramparts were destroyed and the ditches filled in or vaulted. The gateways of the original city wall still remain: the porte Jeune, porte du Miroir, porte de Bâle and porte Haute. The only other vestiges of the medieval fortifications are three towers: the Tour Nessel and the Tour du Diable, which were restored in 1906, and  the Tour du Bollwerk, restored in 1893.

While the ramparts disappeared, the New District was built, thus heralding the age of industrial prosperity in the early 19th century. The district grew up around a triangular garden, the Square de la Bourse, surrounded by blocks of flats with archways and the premises of the Société Industrielle de Mulhouse (an association founded by industrialists in 1826).