"Though this picture is simple. I have done black and white photography for many years and my favorite element of design is contrast. The contrast in this photo takes it from simple to interesting." I think this a fine example of contrast/black and white.
World's most photographed spiral staircase at the Vatican Museums. Designed by Giuseppe Momo in The stairs are actually two separate helixes, one leading up and the other leading down, that twist together in a double helix formation.