Mcarter below mentioned the dry stone walling association, i cannot echo his/her comments enough,
whatever country your in i would hope hey have an authority on dry stone walling which should run cources, i went on one of these for a weekend and leant enough to have a crack at it =)
this took me a good 2 weeks of half days, and as davecm said the perminance of achieving something is amazing =)
I am waiting for some (far too expensive in my opinion) flat topping sontes to go on the top and make it nice and finished. The main bulk of wall is done and awaiting delivery within 2 weeks.
good luck to you all =)


