This image is on its side - the reality is 90 degrees counter clockwise.  but that doesn't matter.   For a web site, the landscape view is easier to project on a 16x9 screen. 

The afternoon light across two silos (one riveted, one cast in place concrete) at St Mary's Cement in Cleveland, Ohio put the helical staircase shadow spectacularly on the concrete silo.  Every detail goes to the focus of the sun.