Newgrange

Newgrange stands in the Boyne Valley of County Meath, Ireland, a large passage tomb built around 3200 BC, making it older than both Stonehenge and the Great Pyramid of Giza. Its circular mound, roughly 85 meters across, covers a long inner stone passage leading to a cross-shaped burial chamber roofed by a corbelled stone vault that has remained watertight for more than five thousand years without the use of mortar. The mound's kerbstones, particularly the large entrance stone carved with spiral and lozenge motifs, are considered among the finest surviving examples of Neolithic megalithic art in Europe. Newgrange is known for a roof-box above its entrance that admits a narrow beam of sunlight into the tomb's inner chamber only around the winter solstice, a deliberate alignment demonstrating precise astronomical knowledge on the part of its Neolithic builders. It forms part of the Bru na Boinne UNESCO World Heritage Site, inscribed in 1993 together with the nearby monuments of Knowth and Dowth.