Horseshoe Curve National Historic Landmark is at jct. 40th St. and Kittanning Point Rd. The site features the Horseshoe Curve, an 1854 engineering marvel that served as a vital link in early westward train travel. In allowing a more gradual ascent to the summit, locomotives were able to scale the Allegheny Mountains for the first time. It is still in use today as the Norfolk Southern main line. An incline plane ride takes visitors to an observation area where they can view the Curve and the Allegheny Mountains.