A nice place to relax is at the "Steinbachtalsperre" near Euskirchen in the south of Cologne, Germany.
There is a big playground and an open air bath for your children and a snugly restaurant for mum and dad.
Look for those early spring pictures at:
http://www.familietille.de/freizeit/steinba.html
Explore this site about the open air bath:
http://www.vffw-steinbach.de/index.html
The german cuisine restaurant has its own beer brewery and a beer garden.
It is called "Waldgasthof Steinbach" and its located at:
N50°35.32' E006°49.88'
Talsperrenstraße 105
53881 Euskirchen-Kirchheim
Phone +49 (0) 22 55 / 95 83 00
N50°35.32' E006°49.88'
Have a nice day there
High
PS: There is also a cache nearby.