Riverside drive viaduct NYC by Martijn van Dam Via Flickr: Explore - #18 The Riverside Drive Viaduct, built in 1900 by the US City of New York, was constructed to connect an important system of drives in Upper Manhattan by creating a high-level boulevard extension of Riverside Drive over the barrier of Manhattanville Valley to the former Boulevard Lafayette in Washington Heights. F. Stuart Williamson was the chief engineer for the municipal project, which constituted a feat of engineering technology. Despite the viaduct's important utilitarian role as a highway, the structure was also a strong symbol of civic pride, inspired by America’s late 19th-century City Beautiful movement. The viaduct’s original roadway, wide pedestrian walks and overall design were sumptuously ornamented, creating a prime example of public works that married form and function. An issue of the Scientific American magazine in 1900 remarked that the Riverside Drive Viaduct's completion afforded New Yorkers “a continuous drive of ten miles along the picturesque banks of the Hudson and Harlem Rivers.”[1] The elevated steel highway of the viaduct extends above Twelfth Avenue from 127th Street (now Tiemann Place) to 135th Street and is shouldered by masonry approaches. The viaduct proper was made of open hearth medium steel, comprising twenty-six spans, or bays, whose hypnotic repetition is much appreciated from underneath at street level. The south and north approaches are of rock-faced Mohawk Valley, N.Y., limestone with Maine granite trimmings, the face work being of coursed ashlar. The girders over Manhattan Explore - #40 Street (now 125th Street) were the largest ever built at the time. The broad plaza effect of the south approach was designed to impart deliberate grandeur to the natural terminus of much of Riverside Drive’s traffic as well as to give full advantage to the vista overlooking the Hudson River and New Jersey Palisades to the west. The viaduct underwent a two-year long reconstruction in 1961 and another in 1987. (source: Wikipedia)