Due to previous military use, ordnance contamination in the terrain can be assumed on most DBU natural heritage sites. Therefore, many of the areas are subject to a trail ban: visitors are not allowed to leave the public, marked trails in accordance with the hazard prevention ordinance.
In the long term, the DBU subsidiary plans to make its areas accessible to walkers at selected locations in order to allow them to experience the beauty of the natural heritage while protecting locals and visitors from potential hazards.