Hello there !
On my mission to climb all 188 of the 2000ft mountains of Wales the most recent ones visited were Gorllwyn and Drygarn Fawr , found high above the Elan Valley , a really remote and desolate place (the hills , not the valley) .Anyway , atop Drygarn Fawr are two huge beehive cairns , and splendid they are too , and though the stones are from the Bronze age (i think) , the cairns were restored early in the last century . There's also an ancient track that passes through the hills . I'm glad i went on a dry day because the whole of the summit plateau between the tops is a vast pathless bog . There's plenty of stuff to visit around here , but sadly didn't get chance , there you go. Cheerz
here's the Wiki : http://en.wikipedia.org/wiki/Drygarn_Fawr
and the Megalithic portal : http://www.megalithic.co.uk/article.php?sid=10037
And some i took :