Newgrange Yet another site with archaeoastronomical significance is a UNESCO World Heritage Site! Found in the Boyne river valley in the County of Meath on the east coast of Ireland, Newgrange is a passage tomb built by Neolithic communities. There are many passage tombs in Ireland, and many of them have astronomical alignments. Newgrange has one of the richest collections of pecked decorations along its walls. Photo by Clive Ruggles Discovered in 1966, dated to 3100 BCE, and reconstructed recently, Newgrange has a 19 metre long passage which leads to a corbel-vaulted inner chamber. It is surrounded by 97 kerbstones. The whole structure is made of stones including quartz and granite. At the Winter Solstice, the chamber is lit upfor 17 minutes by sunlight which shines through a small opening across the entrance.