Wharfedale Lynchets: The historic 'staircase' fields in Yorkshire which date back almost 1,000 years
These intriguing fields in Upper Wharfedale are some of the best-known lynchets in England.
From a distance the horizontal, clearly defined strips look like a staircase rising up the daleside and were formed many centuries ago to allow the growing of crops on steep banks.
Those found between the villages of Burnsall and Linton-in-Craven are thought to have been created between the 11th and 15th centuries.
Other fine examples from the medieval period in the Yorkshire Dales can be seen in Littondale, Malhamdale and Swaledale.
Similar lynchet terraces exist on the chalk slopes surrounding the giant hill figure at Cerne Abbass in Dorset, and near the Cumbrian town of Kirkby Stephen.
The method of agriculture was adopted because early farmers in hill country had to make the best possible use of the land, which meant cultivating the higher contours in order to find space for crops.
They did this by running heavy ox-drawn moldboard ploughs along the bare hillside so that the soil from each pass created a bank on the lower edge, known as a positive lynchet, and a scarp on the upper side called a negative lynchet.
This work created long steps of workable planting beds sometimes so narrow they measured just four or five yards in width.
The crops would have been oats or rye - staples in the diet of the lower classes - and barley, especially a hardy type called bere that was quick to grow and used for bread and ale.
But increasingly from the 15th century onwards much of the Yorkshire Dales landscape became pastureland, and the lynchets were grassed over for sheep grazing.
Much older lynchet terraces exist across Wharfedale from Linton, in the limestone areas above Grassington. These are squarish or rectangular and been dated to prehistoric and Romano-British times.