I was in Washington, D.C. in 2012 for the Wikimania conference. I was only in town for a few days, and didn't really have time for sightseeing, but I took advantage of being jetlagged to go for an evening walk around the National Mall.
I was near the U.S. Capitol as the sun was finishing to set. I particularly like the symmetry of this photo taken at twilight, between day and night, and showing the reflection of the building in the water.
Taking photos at night is always a challenge, particularly when there's a lot of contrast between fight and dark areas. I'm pleased with how this series came out, with dark blue clouds looking so ominous. I'm also happy with how sharp the building's features look, especially considering that I didn't have a tripod on other stabilization system.