The Fort bij De Kwakel is a fort that is part of the Defence Line of Amsterdam (Stelling van Amsterdam). It's located in the village of De Kwakel. It's one of four forts that form the linie Kudelstaart - Uithoorn. To the west is fort bij Kudelstaart, to the east you find fort aan de Drecht and fort bij Uithoorn.
The fort was built in 1890. The main building consists of 18 rooms . The house of the person who manned the fort when there were no troops is also still there. Some of the other buildings have been converted into houses.