The Watermolen Hackfort is located on the estate Hackfort, close to the castle of the same name. The mill was first mentioned in the year 1442, while the current square stone building was built around 1700. The mill is equipped with a water wheel with blades and is powered by water from the Hackfortse Beek. The water wheel drives millstones to grind grain. The water mill also supplies electricity to the electricity network.

In 1952 the mill was shut down because of the poor condition of the wheel and building. At that time the stream also contained too little water to power the mill. In 1981, the estate (with castle and mill) passed into the hands of the Natuurmonumenten and was refurbished. After the water board had ensured that sufficient water flowed through the Hackfortse Beek, a new water wheel was installed in 1998.

Since that moment the mill has been in use. Volunteer millers are sawing wood and grinding grain for cattle feed on hydropower. On Saturdays and on special occasions the mill is open to visitors.