The old Livingston Avenue Bridge as viewed from Corning Preserve. The original bridge here was constructed in 1866 with the first train (called the Augustus Schell) crossing on February 18. The current bridge shown here was rebuilt in 1901, though I've heard that some of the stone supports from the original bridge were reused.
The main section of the bridge swings open on a massive pivot to allow tall boats to pass through.
Looking up at the underside of the bridge, it's easy to see the effects of a century of use and corrosion. But it's estimated that the cost to replace the bridge - which still actively carries both freight and passenger trains across the Hudson River - is well in excess of $50 million.