Paris

Musée de Cluny (National Museum of the Middle Ages)
The Hôtel de Cluny was once the town house of the abbots of Cluny and is now the Musée de Cluny, an important museum containing a variety of artifacts from the Middle Ages. The Hôtel de Cluny is partly constructed on impressive remains of Gallo-Roman baths dating from the 3rd century (known as the Thermes de Cluny) and may still be visited.
more on Wikipedia