Dry-stone dyke

Dry stone, sometimes called drystack or, in Scotland, drystane, 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.

Dry stone 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.

Some dry-stone wall constructions in north-west Europe have been dated back to the Neolithic Age. Some Cornish hedges are believed by the Guild of Cornish Hedgers to date from 5000 BC, although there appears to be little dating evidence. In County Mayo, Ireland, an entire field system made from dry-stone walls, since covered in peat, have been carbon-dated to 3800 BC. The cyclopean walls of the acropolis of Mycenae have been dated to 1350 BC and those of Tiryns slightly earlier. In Belize, the Mayan ruins at Lubaantun illustrate use of dry stone construction in architecture of the 8th and 9th centuries AD.

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.

...
Wikipedia