Mile 0 - This is it, where you journey will either begin or end. This is ground zero, the tidewater lock, the lock that joins Rock Creek and the Potomac River. The towpath ends just past Lock 1 where it joins Rock Creek. Rock Creek winds a short distance through downtown DC before emptying into the Potomac just left of this lock.
This is the mouth of Rock Creek with what looks like the remains of a swing gate. That large and prominent building in the background is the Watergate Hotel. Yes the Watergate which played so prominently during President Nixon's second term. It was named after the canal! It's right by the Gate to the Water.
Thompson's Boat Center, just upriver from the lock is huge and I expect that it contains the nation's strategic reserve of sculling boats. There's acres of them stored over the boat center grounds. Here's a team just starting their trials. That's the Kennedy Center in the background.
Out on the Potomac, their manly biceps are straining.