Beersel is part of Flemish Brabant located between the southern edge of the greater Brussels area and Walloon Brabant. The area is bounded by the Zenne Valley in the west. This is the place where the Lord of Beersel built his fortress.

This fortress with its large moat, impressive towers and thick walls with loopholes and covered ways, is a typical example of medieval military architecture. However, do not expect to find any richly decorated interiors here.