Sully's Renaissance Castle forms, together with it vast park and outbuildings (18C), a fine architectural ensemble. The exterior features four wings flanked by corner towers set to form a diamond pattern and surrounded by moats supplied with water by the River Drée. The imposing North façade, remodelled in the 18C, is preceded by a monumental staircase leading to a terrace overlooking a pond. Inside, note the sumptuous 19C décors, with mementoes of leading figures associated with the place, including Mac-Mahon, the French President of the Republic who was born here in 1808.