All these stones are in shallow valleys

http://www.themodernantiquarian.com/post/57358/maen_hir.html

http://www.themodernantiquarian.com/post/48283/images/coedybedo_standing_stone.html

http://www.themodernantiquarian.com/post/65908/images/tretower_stone.html?stream=site

http://www.themodernantiquarian.com/post/32860/images/fish_stone.html

I dont know if the situations are the same but these are just a few stones ive seen that arent high up , Like Mr H says lets 'ave a look