That heap of metal is what's left of a passenger waiting shelter at the old Elm Park station on the abandoned North Shore rail line. The shelter looked considerably more shelter-like not long ago, although it was mostly hidden by foliage when we looked down on the station from the other direction back in July of 2013. As you can see, the parts of the platforms that were visible then have since been removed, and the area where they stood, beyond the chain-link fence, has been cleared, perhaps for use in the big construction project happening on the Bayonne Bridge (that's the approach to the bridge rising in the background).