Lost in the deep woods sheltering the Manatawny and Ironstone Creeks is a mythical secret valley. Though today only white-tailed deer, great blue heron, and bald eagles know the beauty of this legendary land, it was once the province of pioneers and patriots. Completed by soldiers home from the Civil War just four months after the Transcontinental Railroad united the East and West, the Colebrookdale is a record of epic engineering and heroic human drama. Eight-point-six miles long and a century-and-a-half back in time, the Secret Valley Line beckons you to experience for yourself the unexpected treasures of Southeastern Pennsylvania.