I couldn't have planned this as well as I found it by chance:

Half the chain is illuminated against the shadow;
the other half of the chain is in shadow against the
illuminated wall, and the post divides the image perfectly.

1/500 @ f11, ISO 160, 55mm
Nikon D7100
Nikkor 18-55mm f3.5-5.6

www.JamesCRitchie.com