I used to live in the Ocean View area of Virginia, USA, and also around the nations capital - so F-3 gives me the strangest sense of deja vue at times.
Here is a link to what it used to be like in Ocean View, which is I think where the "Riverboat" drops you off when you do that DLC:
http://en.wikipedia.org/wiki/Ocean_View_Amusemant_Park
When I was there in 2000 - 2002 the roller coasters and the park were pretty much long gone except for the old fishing pier and a park along the shore where they have concerts from time to time.
It still gives me a sort of eerie feeling playing that DLC, and add to that that in the long ago (back in the seventies and eighties) I rode bicycles all over the the northern DC area so that Olney, Bethesda, and all of that seem real familiar.
It's creepy - kind of like the game is taking me back in time in a way...