[Irish_Thatcherite]

That knocks the Ceide Fields in North Mayo off the top of the list; they are only 5000 years old.

[Happygal]

Hey! I wonder if all the Irish Megolithic navvies went off to build the pyramids, same way as the Paddies built the UK highways with McAlpine's Fusiliers? ;-)

[expat_panama]

Davies' The Isles talks about the earliest bones going back around 7,000 years as the area was slow to shake off the glaciers.   The megaliths seemed to have wound down on their own long before the first Celts came up to the 'Green Isles' from the Iberian Peninsula around say, 3,000 years ago.