The southern portal of Toadmoor Tunnel (originally called Hag Wood Tunnel) photographed on 3 October 2022. The 128yd long structure opened in 1840 as part of the North Midland Railway (NMR) line from Derby to Leeds. The tunnel was cut through an unstable hillside on a notoriously difficult line of route, what had initially been expected to be acceptably strong coal-bearing rock turned out to be wet shale. On beginning excavation a landslide occurred, the effects of which can still be seen further up the bank in Thatcher's Wood. The engineer Frederick Swanwick decided to proceed using the cut-and-cover method, with stone retaining walls and invert, and a brick-built masonry arch over the top, which gives it its unusual elliptical shape. Because of this, it took 15 months to build, instead of the planned two.