Just started walking from home towards Grunewald and saw the old US radar station form the distance. My mind was set.
Climbed up the teufelsberg, walked around the radar station, descended towards the Teufelssee, a small pond in the middle of the woods next to the old water works, and back to Grunewald S-Bahn station past the large “Sandgrube im Jagen 86”. Took the 186 bus back to Roseneck.
Note - Hanging “abgeseilt” from the wall of the radar station, a group of dancers was rehearsing a synchronised dance high above the ground.