The Nickey Line is a former railway line that links Harpenden, Redbourn and Hemel Hempstead. It is approximately 8.5 miles long and suits both walkers and cyclers. The route forms part of route 57 of the National Cycle Network.
The Nickey Line can be joined at a number of access points along its length. Some access points are via steps due to the embankments of the original railway line. Level access points exist at Adeyfield Road, Eastman Way and Redbourn Road in Hemel Hempstead; at Gaddesden Lane, Chequers Lane, High Street and Redbourn Lane in Redbourn and at Townsend Lane, Park Hill, Moreton End Lane in Harpenden.
The route passes through Yew Tree Wood, open countryside, past Hornbeam and Hazel coppice and through land used for agricultural crop research. The wood and grassland habitats are home to a wide diversity of animals, including butterflies, shrews, foxes and birds.