What are sunken lanes?
Sunken lanes are roads or tracks that are incised below the general level of the surrounding land, often by several metres. They are formed by the passage of people, vehicles and animals and the action of running water. They may be active (incising) or inactive at the present time, and are often hundreds of years old. Many are metalled as roads have been laid within them.
Location and origin
Sunken lanes are found in many European countries. In general, they are associated with areas of soft rocks and a long history of human occupation. They are particularly frequent in areas with soils derived from wind-blown dust (‘loess’).
In France, they are known as ‘chemin creux’, and in Germany as ‘Holweg’. 'Holloways' is also a common name for them in England.
In southern England, they are impressively developed on the Bridport Sands around Yeovil and on the Lower Greensand in Surrey and Sussex.
It is difficult to date sunken lanes. Those around Midhurst in West Sussex appear to connect valley-bottom villages at crossing points of the River Rother with upland areas that would have been a timber and pasture resource. The movement of animals from winter grazing in the valleys to summer grazing on more upland areas is referred to as ‘transhumance’, a system practiced globally.The villages in the area are of Saxon origin, therefore suggesting that the lanes are at least 1500 years old.
Sunken lanes have acted as strategic routeways in times of battle. They are repositories of geological information (exposures in roadside banks), and provide habitats for animals such as badgers, foxes, rabbits and birds, and routeways for bats.
Sunken lanes in the South Downs National Park
Gilbert White, vicar of Selbourne, was well aware of sunken lanes in the South Downs, and wrote about them in a letter to celebrated naturalist and traveller, Thomas Pennant, in the mid-1760s:
‘Among the singularities of this place the two rocky hollow lanes, the one to Alton, and the other to the forest, deserve our attention. These roads, running through the malm lands, are, by the traffick of ages, and the fretting of water, worn down through the first stratum of our freestone, and partly through the second; so they look more like water-courses than roads…In places they are reduced sixteen or eighteen feet beneath the level of the fields.’
One of the principal routes between fields and rivers is via sunken lanes. Sediments travelling from valley-side sources (mainly arable fields) reach rivers and can lead to problems for fish breeding and invertebrates, as has been seen in the River Rother. At times of heavy rainfall, muddy flows can move down sunken lanes and cause repeated flooding of villages, such as at Easebourne in West Sussex, before reaching the river.
Sunken lanes - why should we care?
Sunken lanes are much neglected features of our landscape. They form essential networks for rural communication formed by hundreds of years of human, vehicular and animal movements aided by running water. They are of interest to geologists and ecologists and in certain areas they have a profound impact on patterns of flooding and river pollution.