The Railroaders Memorial Museum also operates the World-Famous Horseshoe Curve—one of the eight engineering marvels of the world. In the early 1850s, the massive front of the Allegheny Mountains, standing 2,161 feet above sea level, blocked westward advance. This obstacle culminated in the creation of the Gallitzin Tunnels and the Horseshoe Curve, both of which were dug out of near-impenetrable geographic formations. Using switchbacks, excavations, and pure innovation, engineers reduced grades and effectively conquered the mountains. To conduct these laborious endeavors, the Pennsylvania Railroad hired job-hungry Irish immigrants. The hazardous work lasted three grueling years with the rail line officially opening on February 15, 1854. The end result was nothing less than monumental. The completion of the Curve was widely celebrated and heralded throughout the state as a grand opportunity. Over the next century-and-a-half, this now-iconic railroad link became a target of Nazi spies, a tourist destination, and one of the primary east-west arteries of railroad travel in the nation. Today, visitors from around the globe trek to the World-Famous Horseshoe Curve to reflect on its incredible past and compelling scenery. The landmark includes an observation area, an exhibit hall, and a museum store. For more insight, check out the Railroaders Memorial Museum, full of fascinating artifacts and stories of the railroaders who left an imprint on their communities, industry, and nation.