This a classic Pittsburgh run. Start at Smithfield Bridge, which is easily accessible from downtown (Blvd. of Allies, Fort Pitt Blvd.), cross bridge, and run along south side through pleasant Southside Riverfront Park. Cross back over at Hot Metal Bridge, and run along the grittier north side, which includes passing by the Allegheny County Jail, to downtown.
Note: brief street section just after Smithfield Br.