Rockville Bridge

The Rockville Bridge is the longest stone masonry arch railroad viaduct ever built, with forty-eight 70-foot spans and a total length of 3,820 feet. The bridge crosses the Susquehanna River about 5 miles north of Harrisburg, Pennsylvania. The eastern end is in Rockville and the western end is just south of Marysville.

Completed in 1902 by the Pennsylvania Railroad, it remains in use today by the Norfolk Southern Railway and Amtrak's Pennsylvanian route.

The bridge was listed on the National Register of Historic Places in 1975 and was designated as a National Historic Civil Engineering Landmark in 1979.

Source: Wikipedia