from the 145th Street Bridge over the Harlem River toward the Macombs Dam Bridge, the Four Sisters, and the High Bridge Water Tower. The wooden structure below, running parallel to the river, lines up with the center span of the bridge when the bridge rotates open to let river traffic through. This sort of feature is common to swing bridges; according to Wikipedia, it protects the center span from being struck by a passing ship while in the open position. It seems like it would also allow for easy access to the underside of the span for repair work. (That's a worker in an orange safety vest snapping a photo near the end of the structure.)