DR Shunt signal, Berliner S-Bahn Museum
I'm slightly disappointed by this photo: it does not show how just how luminous and orange the "W" of the shunt signal in the foreground is. The sign in the background means "10kph restriction ahead".
The Berliner S-Bahn Museum is located just outside the city in Griebnitzsee, a suburb of Potsdam. It is normally open on the second weekend of each month.