Hirschacker und Dossenwald, Nature reserve in Mannheim and Schwetzingen, Germany

Hirschacker und Dossenwald is a nature reserve between Mannheim and Schwetzingen, covering 128.9 hectares of inland dunes up to 13 metres high that drop steeply to the east. Most of the area is wooded, mainly with pines, plus black locust and mixed deciduous forest. Open sand and clearings in the southern Hirschacker, kept open by earlier military use, support sand grasslands and heath.

The protected area was designated in 1993 and includes land previously used for military purposes. This earlier use shaped the landscape, particularly creating open clearings in the southern Hirschacker section.

The name Dossenwald derives from "Dosse", an Old German word for pine, the tree that dominates the reserve's loose pine woods. The open sand areas, kept free of trees by earlier military use, instead support sand grasslands and heath.

The reserve is accessible via marked walking paths that guide visitors through the area. Staying on these designated trails helps protect the habitats while offering the best opportunities for observing the landscape.

The dunes rise up to 13 metres and drop steeply to the east, while the western side is open drifting sand and the eastern side is Neckar alluvium. Since early 2020 the Karlsruhe regional council has fenced off sensitive zones and set up 1,200 metres of visitor guidance, removing 850 metres of sand and earth paths.