The planning of Riverside Park began in 1873, not long after Central Park was opened to the public. The Park was developed from a narrow strip of rocky cliff on the banks of the Hudson River, and stretches almost continuously from Seventy-Sixth Street to One Hundred Fifty-Eighth Street, save for a ten block section of the river bank, from One Hundred Twenty-Fifth to One Hundred Thirty-Fifth Streets. The initial plan for the Park – conceived by Central Park designer Frederick Law Olmestead – called for a scenic parkway to wind along the Park’s rocky bluffs, and the viaduct in chapter twenty is the bridge which extends that drive over the ten blocks where there is no park. I was not able to discover at what year the viaduct was constructed. It is rendered here from the east looking west along what one of the cross-streets over which it passes. The composition in the drawing bares a striking resemblance to that of chapter twenty-three, "High Bridge."