Maximilien de Béthune, Marquis de Rosny and Duc de Sully (1559-1651) built this Louis XIII-style château in the early 17C and created the original gardens with copses and “grottoes” in the contemporary fashion, later remodelled as English-style parkland by Marie-Caroline de Bourbon-Sicile. Widow of the Duc de Berry and pregnant with the future Comte de Chambord, she moved to Rosny (bought with her dowry) in 1820. Among other things, she built an almshouse, today the Hospice St-Charles cultural centre.