Tunkhannock Viaduct

Also known as the Nicholson Bridge and the Tunkhannock Viaduct, the Tunkhannock Creek Viaduct is a concrete deck arch bridge that stretches over the Tunkhannock Creek in Nicholson, PA. The viaduct measures 2,375 long and towers 240 feet making this the largest structure in the world when completed in 1915. It's still merited the title of "largest concrete bridge in America, if not the world!" The bridge is still used today.