The Woodhead Tunnel is a railway tunnel located in the Pennines mountain range in northern England. It was completed in 1845 and is approximately 3.75 miles (6 km) long. The tunnel connects the towns of Glossop in Derbyshire and Hadfield in Greater Manchester, facilitating the movement of goods and passengers through the region. Originally built for the Manchester, Sheffield and Lincolnshire Railway, the Woodhead Tunnel played a significant role in the industrial development of the area. It was electrified in the 1950s, allowing for faster and more efficient train services. The tunnel is now closed to regular rail traffic but remains an important part of railway history.