Keiheuvel is a recreational domain and nature reserve in the Belgian municipality of Balen. It is located immediately south of the basin of the Balense part of Wezel. The entire domain covers 108 hectares, of which 60 hectares are a nature reserve and the rest is a recreational area. 34 hectares are managed by Natuurpunt. The area is European protected as part of the Natura 2000 area Upper reaches of the Grote Nete with Zammelsbroek, Langdonken and Goor.
The nature reserve is an area of dry coniferous forests, heathland and drifting sand. In fact, it is a cover sand ridge oriented in an east-west direction that forms the division between the valleys of the Grote Nete and the Molse Nete. The woodlark and sparrowhawk breed here, and the wheatear has a resting area here. The area is rich in mosses, lichens and fungi. Various rare insects are also found here. The area is adjacent to the De Most nature reserve, and an 8 km walk through both areas has been set out.
In the recreation area there is the Keiheuvel (glider) airport, which opened in 1956, and there is a sports hotel and a campsite, as well as catering establishments, a swimming pool, a playground and a petting zoo. Here you can practice various sports.