National Geographic News
Artifacts unearthed at the site include a stone axe head, a pottery fragment, and an ornamental pin. An ancient buried dog was also excavated nearby.
Archaeologists say the monument probably formed part of an important ceremonial complex centred on the Hill of Tara, where remains date back to the Stone Age.
Archaeologist Joe Fenwick of the National University of Ireland, Galway, described the Hill of Tara as Ireland's equivalent of Stonehenge or Egypt's Pyramids.National Geographic