Postal delivery

Is it inevitable that cities have graffiti? Or is it something about the 1950s buildings in Berlin that attracts it? But that wasn't the point of this photo - it's about the postman's cart, and how the mail gets delivered. The postie has keys for the buildings on the route and takes the mail to each door on the staircase. That can add up to a lot of stairs.

The bike is presumably for routes that cover more ground -