From the fountain pond, the water of the water arts flows over man-made but natural-looking waterfalls to the castle pond, the so-called "Lac". In the 18th and 19th centuries, it was considered chic to give buildings - or, as in this case, a lake - French names. This "Lac" was created from a small fish pond by Heinrich Christoph Jussow in the period 1785-91.
The water still leaves the park today as a meadow stream via the drain at the eastern end of the Lac, which was created by Jussow in 1789. In the past, the water in the stream flowed off through Kassel into the Fulda, but today it is channelled underground to the Fulda.