Got one here in the Bay Area: http://en.wikipedia.org/wiki/Drawbridge,_California
Fun, though dangerous [active train track; passenger trains pass at 100kph], place to visit. Just walk out the trails from Alviso in the south bay. I've done it about 3 times. Old dead buildings falling into the marsh. Walkways lead from the tracks to the water's edge (for maintenance?).
Note: it's illegal to visit (dangerous + nature sanctuary), so go at night..