Located just outside the Haltern Water Reservoir, the 90-hectare "Westruper Heide" is a impressive heathland. The remaining area of the sand heaths, which used to dominate the Haltern region, lies on a post-glacial dune landscape. Heavy agricultural use since the Middle Ages pushed the original mixed forest back through firewood and cattle grazing and reduced the humus layer by plagiarism. The soil was only overgrown by frugal plants such as broom heath or juniper. In the course of the industrialization of the nearby Ruhr area, this heath landscape receded when pines were planted extensively for the Ruhr mining industry. The trunks were much sought after as pitwood.
In 1936, around 63 hectares of them were nature protected in order to preserve the once extensive heathland for future generations and continue to make it experienceable. Since 1993, 200 Heidschnucken and 10 goats have been grazing for five months of the year. In addition, in January or February, the old areas are processed by deliberate burning. The resulting ash acts as a fertilizer and rejuvenates the heath. In addition to the up to eight meter high juniper bushes, there are some solitary trees. In addition to the broom heath, the English broom and the bell-heath, as well as various lichens and mosses, are growing. In particular heat-loving insects and birds as well as reptiles populate the heathland.
The habitat mosaic of heathland provides numerous, now endangered plant and animal species a home. In the area there are the following, particularly sensitive landscape characteristics:
-Sand heaths inland dunes,
-Sand dry grassland on inland dunes,
-rare and endangered juniper stands on dwarf shrub heaths
-nutrient-poor wetland ecosystems (Heideweiher).