The d’Agay mansion was a canon’s house. It was rebuilt in 1745 and is today the home of the archbishop. The architectural style is very refined and not at all like other homes built in Besançon around the same time, which were much more austere. The facade is rusticated (the stones jut out from the wall) at the joints and the concave ends of the wings soften the look of the ensemble. The ornamentation is rocaille in style.

You can see this if you look at the top of the middle part of the facade: everything evokes the form of a C, including the shells and the leaves that encircle the rounded medallion meant for the d’Agay family’s coat of arms. The decoration on the entrance gate uses the same motif, as you can see in the curving movement of the cartouches surrounded by shells at the top of the front gate pillars, and in the wrought iron tangled briars that add protection to the courtyard walls.