I live in downtown DC. I go running around the Mall a few times a week early in the morning before work, and I bring a small Sony mirrorless camera with me. The morning I took this photo there was low-lying fog, but it was strange in that the fog seemed to be more of a wall that stopped just short of the Washington Monument, as opposed to the usual sort of fog that obscures the top portion of the Monument. It took me a minute to process what I was seeing, but then I was hit with the realization that the powerful LED lights that illuminate the Washington Monument at night were allowing the Monument to cast a shadow on a wall of fog that, for reasons I can't explain, stopped just short of the Monument.