Ability to survive cold, damp weather and an innate aesthetic value add to the desirability of dry-stone walls. Many of Ireland's walls both mortared and dry-stone, have been built within the past 150 years. Irish stone structures commonly utilize materials such as sandstone, limestone, basalt and granite. Sandstone, a soft sedimentary stone, often appears in walls, buildings and elaborately carved Celtic high crosses. Unfortunately, it weathers poorly.
Limestone appears mostly in monuments and in decorative and facing work.
Often, highly polished limestone served as a less expensive alternative to marble. Basalt, an igneous stone, creates impressive natural structures, like Giant's Causeway on the Antrim coast of Northern Ireland. Builders incorporate it into boundary walls and rough buildings. Skilled builders use granite to create structures with precise dimensions. Single stone walls measure one stone deep.