The remains of a timber circle from more than 4,000 years ago have been uncovered by archaeologists in County Tyrone.The timber circle was found by the Headland Group near Ballygawley in 2006/2007 as part of an excavation project linked to the A4 and A5 road improvements scheme. Project Officer at Headland Archaeology, Kirsty Dingwall, said radiocarbon dating had confirmed it was from around the middle of the third millenium BC, "although some elements of it may be earlier". "The specific use of timber circles are not well understood but it is thought that they were used as ritual sites, perhaps...