Five hours in NYC

Thanks to a travel miscalculation, I've got 5 extra hours in NYC between flying into JFK and taking Metro North upstate. I've decided my destination will be The High Line, a new public park built on a defunct elevated rail line. I'm particularly looking forward to The River that Flows Both Ways, an public art piece that includes 700 panes of glass matched to the color of the Hudson in 700 photos taken once a minute. I'm thinking, too, of paying a visit to my grandparents' old apartment at 22 Cornelia Street in Greenwich Village.

Below is the view from 22 Cornelia Street in the late 1940s: