Many housing estates throughout London are surrounded by black steel and mesh railings with peculiar notches around the edges. Although at first glance they appear to be some quirky architectural design, the notches have a purpose—or rather, had a purpose. These steel railings originally functioned as stretchers used to carry the wounded during the Second World War. The curves or the notches you see were the legs upon which the stretchers were laid on the ground. After the war was over many of these stretchers were repurposed to replace fencing that were lost in the war.