This vast rectangular esplanade is surrounded by charming old houses: the Maison aux Quatre-Pignons (15C), Maison des Petits-Plaids (13C) and Hôtel de la Coquille; the remains of the 12C Saint-Thibault Church also stand here. In the middle of the square, next to the well with a wrought iron cage, is the Croix des Changes, where the counts of Champagne posted their edicts.