There are many stone bridges along the GW Parkway. The one in the photo above is located near one of my favorite sunset spots, Riverside Park. This vantage is located about halfway down an unofficial trail that leads to a rocky beach along the Potomac River.
In order to capture the full range of detail against a backlit sky, I hand-blended three varying exposures together in Photoshop. This is the same idea as shooting HDR (high-dynamic range), but with much greater finesse, control, and, ultimately, a more realistic photograph.