Changes

Take the S9 from Bern Hauptbahnhof to the end stop (Unterzollikofen), then walk over the fields eastwards to the rest area "Grauholz", it's not that far all in fairly walkable distance and , besides, probably a pretty lovely between April walk bin the spring and August summer months due to the sunflower fields (been there in late September and it was still great). No controls in the S-Bahn. Take a picture from the map with your camera, might come handy. Best option fur sure!