Constructed circa 1730-1760 to carry the Raritan Road over Green Brook near its confluence with the Raritan River at the village of Bound Brook, the Old Stone Arch Bridge is a three span, rough-cut stone arch structure with buttresses between the arches on the south face. During the 1840s, the channel of Green Brook was altered by railroad construction in the area, and in 1880 the waterway was completely rerouted to the east, leaving only a small drainage channel beneath the Old Stone Arch Bridge. The area surrounding the bridge was filled in the decades that followed. As a result, today much of the Old Stone Arch Bridge lies below-ground. The upper portion of the south parapet wall is visible above-ground; constructed of rough-cut rubble laid in irregular courses with a sandstone capstone, this parapet was added during the nineteenth century. The north parapet has been removed to the level of the roadway, and the north face is completely buried by a sloped embankment rising to a commercial building located on the fill to the north. Portions of the capstone on the south parapet are missing, and all of the capstones were removed on the north side when the parapet was lowered; however, most have been found in the immediate area. Some of the capstones were used to build an extant staircase north of the bridge, and others have been located in the fill surrounding the structure. - NRHP, 27 June 2008