terminate at Riverside Drive and 158th Street. Riverside Drive Viaduct The elevated steel highway of the Riverside Drive Viaduct, built in 1901, runs between Tiemann Place and 135th Street above Twelfth Avenue. It is shouldered by masonry approaches, though the span proper was made of open hearth medium steel, comprising twenty-six spans, or bays. The south and north approaches are of rock-faced Mohawk Valley limestone with Maine granite trimmings, the face work being of coursed ashlar. The girders over Manhattan 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. F. Stuart Williamson was the chief engineer for the viaduct, 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 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." The viaduct underwent a two-year-long reconstruction in 1961 and another in 1987. Buildings and monuments Residential buildings The eastern side of Riverside Drive was once a series of luxuriously finished rowhouses interspersed with free-standing nineteenth century mansions set in large lawns. Today, it is lined with apartment buildings such as the Normandy and the Master Apartments, as well as some remaining town houses from 72nd to 118th Streets. The brick-faced Schwab House occupies the site of "Riverside", built for steel magnate Charles M. Schwab, formerly the grandest and most ambitious house ever built on Manhattan Island. Among the more eye-catching apartment houses are the curved facades of The Colosseum and The Paterno and the Cliff-Dwellers Apartments at 96th Street, with mountain lions and buffalo skulls on its friezes. The Henry Codman Potter house at 89th Street is one of the few remaining mansions on Riverside Drive; it houses Yeshiva Chofetz Chaim. The Master Apartments at 310 Riverside Drive, a landmarked