▁Initial ▁to ▁Master ▁C raft s man . ▁ ▁Notable ▁examples ▁include : ▁ ▁M our ne ▁Wall : ▁twenty - two ▁mile ▁long ▁wall ▁in ▁the ▁M our ne ▁Mountains ▁location ▁in ▁County ▁Down , ▁Northern ▁Ireland ▁ ▁Ott en by ▁nature ▁reserve , ▁built ▁by ▁Charles ▁X ▁Gustav ▁in ▁mid ▁ 1 7 th ▁century , ▁Ö land , ▁Sweden ▁ ▁Other ▁uses ▁▁ ▁While ▁the ▁dry ▁stone ▁technique ▁is ▁most ▁commonly ▁used ▁for ▁the ▁construction ▁of ▁double - wall ▁stone ▁walls ▁and ▁single - wall ▁retain ing ▁ter rac ing , ▁dry ▁stone ▁sculpt ures , ▁buildings , ▁fort ifications , ▁brid ges , ▁and ▁other ▁structures ▁also ▁exist . ▁ ▁Trad itional ▁tur f - ro of ed ▁High land ▁black h ouses ▁were ▁constructed ▁using ▁the ▁double - wall ▁dry ▁stone ▁method . ▁When ▁buildings ▁are ▁constructed ▁using ▁this ▁method , ▁the ▁middle ▁of ▁the ▁wall ▁is ▁generally ▁filled ▁with ▁earth ▁or ▁sand ▁in ▁order ▁to ▁eliminate ▁dra ug ht s . ▁During ▁the ▁Iron ▁Age , ▁and ▁perhaps ▁earlier , ▁the ▁technique ▁also ▁was ▁used ▁to ▁build ▁fort ifications ▁such ▁as ▁the ▁walls ▁of ▁E ket orp ▁Castle ▁( Ö land , ▁Sweden ), ▁Ma iden ▁Castle , ▁North ▁York shire , ▁Re eth , ▁Dun l ough ▁Castle ▁in ▁south west ▁Ireland ▁and ▁the ▁r amp art ▁of ▁the ▁Long ▁Sc ar ▁Dy ke . ▁Many ▁of ▁the ▁dry - stone ▁walls ▁that ▁exist ▁today ▁in ▁Scotland ▁can ▁be ▁dated ▁to ▁the ▁ 1 4 th