I love being outdoors and meeting new people. There's always the wonderful possibility that something unique happens. That's why my camera is always with me.
Recommended places:
In Cologne you definitely have to visit the Hohenzollern Bridge and promenade along the rhine river. From there you have a beautiful look towards the old town and of course the cathedral (Kölner Dom). Go there in the evening during sunset and golden hour. It's so worth it!