Blisworth Tunnel sections lined with pre-cast concrete rings. It was also used to test out the materials that were later used on the Channel Tunnel. An unused ring is on display near the south portal. Blisworth Tunnel Blisworth Tunnel is a canal tunnel on the Grand Union Canal in Northamptonshire, England, between the villages of Stoke Bruerne at the southern end and Blisworth at the northern end. The northern end is about from the northern end of the Grand Junction Canal at Braunston, Northamptonshire and the southern end about . At 3,076 yards (2,813m) long it is the third-longest navigable canal tunnel
Union Canal (Pennsylvania) closure in 1881. In April 1950, the Union Canal Tunnel was purchased by the Lebanon County Historical Society. The tunnel was placed on the National Register of Historic Places on October 1, 1974. It was designated a National Historic Civil Engineering Landmark in 1970. On April 19, 1994, the tunnel was designated a National Historic Landmark by the Secretary of the Interior Bruce Babbitt. The tunnel is open to visitors in the Union Canal Tunnel Park. A restored portion of the canal along Tulpehocken Creek is maintained by the Berks County Parks System at the Union Canal Towpath Park in