The Horseshoe Curve is a famous railroad curve located in Pennsylvania, USA. It was constructed in the 1850s to allow trains to navigate the steep terrain of the Allegheny Mountains. The curve is notable for its unique shape, resembling a horseshoe, and is a key part of the Norfolk Southern Railway. This engineering marvel spans about 1,300 feet and has a 220-degree arc. It allows trains to gain elevation while maintaining a manageable grade. The Horseshoe Curve is also a popular tourist destination, attracting visitors interested in railroad history and scenic views of the surrounding landscape.