At the north end of the Old Town waterfront is the end of a spur that gets switched by Norfolk Southern infrequently. The line was mainly used for the about-to-be-closed electrical generating station further up the spur but one or two boxcars are occasionally spotted at the warehouses on either side of Union Street. Odds are not very good you'll catch any action but if you get lucky it is fun to watch.
The spur was originally the easternmost trackage of the Washington & Old Dominion RR and IIRC originally served piers for transloading cargo to and from ships on the Potomac River.
