Tunkhannock Creek Viaduct (also known as the Nicholson Bridge and the Tunkhannock Viaduct) is a concrete deck arch bridge on the Nicholson Cutoff rail segment of the Norfolk Southern Railway Sunbury Line that spans Tunkhannock Creek in Nicholson, Pennsylvania. Measuring 2,375 feet (724 m) long and towering 240 feet (73.15 m) when measured from the creek bed (300 feet (91.44 m) from bedrock), it was the largest concrete structure in the world when completed in 1915 and still merited "the title of largest concrete bridge in America, if not the world" 50 years later.