This private mansion was built in the 17th century by Désiré de Moustiers, former consul of Marseille. Several owners followed one another until it was bought by the municipality of Cassis in 1938. The building became the Town Hall from 1945. It has been listed in the inventory of historic buildings since 1984 for its rich heritage: living room d'honneur with its coffered ceiling, Renaissance fireplace, chapel with decorated ceiling, Louis XIII windows, paved courtyard, entrance hall and staircase with its baluster banister. Medieval vestiges are visible from the ground floor thanks to a floor of glazed tiles.