Rare animals and plants plus history: A hiking trail along the former Westwall from the Nazi era starts in the Eifel town of Dasburg an der Our. On 2.8 kilometres and 13 information boards, hikers learn about the history of the military structure that was built on the western border of the former German Reich until 1940.

They are also shown how important the ruins are as a habitat for rare animal and plant species. There are bats, wildcats, dragonflies and lizards as well as rare ferns, mosses and lichens.

The hiking trail "From Grey to Green" illustrates how to safeguard those ruins and structures without destroying monuments and biotopes.

Several information boards describe the ruins and topics from nature conservation, information on the historical background and the construction of the fortress.