Robertson Hall (Woodrow Wilson School of Public and International Affiars), Princeton University.
This is a shot of the exterior pillars of Robertson Hall. The shot is rotated clockwise 90 degrees, so the sky would actually be to the right. The light regions are the outward facing sides of the pillars. The darker regions are the sides of the pillars perpendicular to the building. So, each pillar consists of a light region (left) and a dark region (right).
However, what I like about this shot is that its essentially an optical illusion. It looks to me as if this is a series of curved benches in some kind of amphitheater. In this way, the darker regions look like the left-facing front edge of the "bench" on its right. In other words, your mind (or at least my mind) wants to associate the dark region of one pillar with the light region of the adjacent pillar.
I know that's a really confusing explanation. Hopefully it makes some sense.
Incidentally, I think this is one of the most interesting buildings at Princeton. It was designed by Minoru Yamasaki, who also designed the (former) World Trade Center.