Alexandria Canal Aqueduct

Mile 1.07 - The Francis Scott Key Bridge you see to the left replaced the Alexandria Aqueduct.  Originally, it was an aqueduct which took boats across the Potomac from Georgetown to Alexandria.  It was later drained and used as a bridge.  

It's here the towpath leaves the city and is surrounded by trees instead of office buildings and restaurants.

Aerial view of the bridge.

A hobo sleeps by the graffiti encrusted walls of the aqueduct.  This is right in the flight path of Reagan National Airport but I guess he's used to all the planes going by.