The town hall of Cassis is a mansion of the early seventeenth century built by Désiré de Moustier, former Consul of Marseille. You can see a Grand Siècle staircase and a lounge of honor with a coffered ceiling and a period fireplace topped by the portrait of Pierre de Garnier, Secretary of the King in the Parliament of Aix and the Cassis Consul in the 18th century.
The ground floor has under a glazed floor, the remains of a medieval kitchen.
Acquired by the municipality of Cassis in 1938, the building was fully restored in the late 1980s.