imagine that there is a fine on these stone walls, too. I did find this wiki entry:
http://en.wikipedia.org/wiki/Dry_stonein part...
Location and terminology
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 also may be found in the Apulia region of Italy as well as New England, New York, New Jersey, and Pennsylvania in the United States. 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 New England and are a notable characteristic of the bluegrass region of central Kentucky, where they are usually referred to as rock fences. This type of structure is common in areas with rocky soils, such as New England, Central Kentucky, and the Napa Valley in north central California. The technique of construction was brought to America primarily by Scots-Irish immigrants.
Artwork embedded in a dry stone wall in Italian SwitzerlandSimilar walls also are found in the Swiss-Italian border region, where they often are used to add the missing sides of natural covered spaces under large natural stones.
Dry stone wall construction was known to Bantu tribes in southeastern Africa as early at 1350 to 1500 AD. When some of the Zulu migrated west into the Waterberg region of present day South Africa, they imparted their building skills to Iron Age Bantu peoples who used dry stone walls to improve their fortifications.
In Peru in the fifteenth century AD, the Inca made use of otherwise unusable slopes by dry stone walling to create terraces. They also employed this mode of construction for free-standing walls. Their ashlar type construction in Machu Picchu uses the classic Inca architectural style of polished dry-stone walls of regular shape. The Incas were masters of this technique, in which blocks of stone are cut to fit together tightly without mortar. Many junctions are so perfect that not even a knife fits between the stones. The structures have persisted in the high earthquake region because of the flexibility of the walls and that in their double wall architecture, the two portions of the walls incline into each other.