One of the real gems of Washington D.C. is the C&O Canal. This follows the Potomac River from Georgetown all the way to Cumberland Maryland. The canal tow path is ideal for running as it provides a low impact surface, is shaded and—above all—free of traffic. Had a nice 12 km out and back. Brought back lots of great memories of running here when we lived in Virginia. Did a lot of marathon training here! Just look at the photos and you will see why.