Boisbonnard is a fairly attractive ensemble and was extensively altered in 1856.
This private castle is an old fortress of which only:
- the wide medieval moats in their entirety and which form 2 quadrilaterals and a 3-sided figure
- 5 cylindrical towers including the South-East tower pierced with circular loopholes called the “couleuvrine tower”.
The surrounding walls disappeared, the eastern ones were pulled down in 1856.
Access is controlled by 2 entrance towers, capped with pepper shakers, guarding the wooden footbridge which replaced the drawbridge. A portal with a curved pediment connects them.
The enclosure demolished in the last century has retained 3 corner towers.
The current castle was built in several stages. The residential building, which dates from the 16th century, had its facades completely redesigned in 1856. Part of it disappeared at the beginning of the 20th century.
To the south-west, a main building covered with a 4-pitched roof and presenting stone windows on the ground floor had been lined with another building in 1731; these buildings were demolished in 1979.
The outbuildings near the front door were built in Renaissance style around 1856 in place of the old farm buildings.
Numerous renovation and restoration works have been carried out since 1994.
During the cleaning of the moat an oak door was discovered under the water level. We can assume that there was an underground passage between the castle and the village church or to other undergrounds.