National Historic Landmark-Union Canal Tunnel

Tunnel construction technology of the early 19th century was a relatively crude, tremendously arduous, and fairly dangerous undertaking.

Constructed between 1825 and 1827 as part of an 80-mile canal, the Union Canal Tunnel is the oldest extant canal tunnel in the United States.

The canal was planned to carry passengers and freight between Philadelphia and Harrisburg, facilitating commerce between Pennsylvania's major urban center and the resource-rich interior.

The tunnel is located at the point of highest elevation of the canal.

Courtesy National Park Service National Historical Landmarks