Drystone

Dry stone (also called drystack) is a building method by which structures are constructed from stones without any mortar to bind them together. Dry stone structures are stable because of their unique construction method, which is characterized by the presence of a load-bearing façade of carefully selected interlocking stones. Dry stone technology is best known in the context of wall construction, but dry stone artwork, buildings, bridges, and other structures also exist.

A dry stone wall, also known as a dry stone dyke, drystane dyke, dry stone hedge, rock fence or stone fence, is a wall constructed from stones without mortar to bind them together. As with any dry stone construction, the structural integrity arises from compressional forces and the interlocking of the stones. Such walls have been traditionally used in building construction as field boundaries and garden or churchyard walls, and on steep slopes as retaining walls for terracing.

Terminology varies regionally. When used as field boundaries, dry stone structures often are known as dykes, particularly in Scotland. Dry stone walls are characteristic of upland areas of Britain and Ireland where rock outcrops naturally or large stones exist in quantity in the soil. They are especially abundant in the West of Ireland, particularly Connemara. They may also be found throughout the Mediterranean, including retaining walls used for terracing. Such constructions are common where large stones are plentiful (for example, in The Burren) or conditions are too harsh for hedges capable of retaining livestock to be grown as reliable field boundaries. Many thousands of miles of such walls exist, most of them centuries old.

In the United States they are common in areas with rocky soils, such as New England, New York, New Jersey, and Pennsylvania and are a notable characteristic of the bluegrass region of central Kentucky as well as Virginia, where they are usually referred to as rock fences or stone fences, and the Napa Valley in north central California. The technique of construction was brought to America primarily by English and Scots-Irish immigrants. The technique was also taken to Australia (principally western Victoria and some parts of Tasmania and New South Wales) and New Zealand (especially Otago).

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