Gwynedd Archaeological trust carried out trial excavations on behalf of the Welsh Office in advance of the new A55 Trunk road across Anglesey into Holyhead.  As a result, a new site was discovered at Ty Mawr farm, Kingsland Holyhead consisting of a number of stone-lined graves, all of which were orientated east-west, and which contained  no grave goods.  The site was interpreted as a cemetery dating from the 6th to 9th century AD.  The stone-lined graves are often called cists, from the Welsh work "cist" meaning chest, although also used to mean coffin.  In addition to the cemetery, other features were visible which suggested Prehistoric activity on the site.
  In January 1999, Gwynedd Archaeological Trust began full excavation of the site with funding from UK Highways and under the management of Richards Moorehead & Laing.  This has shown that the original interpretation was correct and that the site consists of a cemetery, of at least 36 stone-lined graves, which are almost certainly of the 6th to 9th century date.  There are no skeletons remaining in the graves, because the acid soils have dissolved the bone, as is usual on cemeteries in Anglesey.
    Another feature of the site is visible as two concentric rings of small stone which are placed in trenches 20cm wide and 30cm deep.  The larger ring is 12m in diameter.  A number of ditches of 17th or 18th century date cut across the site, and across the stone ring.  We do not yet know for certain what the circular feature represents, but it may be a Prehistoric round barrow, dating from around 1500 to 2000 BC or it may be a central feature connected with the cemetery.