This UNESCO World Heritage Site is Newgrange, the ‘Mother Ship’ of all Irish ancient monuments. It is part of a complex of at least 35 similar type monuments built along a bend of the River Boyne known collectively as Brú na Bóinne. It was built during the Neolithic period 500 years before the Great Pyramid of Giza by a farming community that prospered on the rich lands of the Boyne Valley. It has been classified as not only a passage tomb but also as a place of astrological, spiritual, religious and ceremonial importance similar to a present day cathedral. It covers one acre and has 97 kerbstones, some of which are richly decorated with megalithic art. The 19 metre long inner passage leads to a cruciform shaped chamber with a corbelled roof that has never leaked. This magnificent feat of engineering brought enormous granite boulders from the coast (20 miles away) and and quartz from the Wicklow Mountains (nearly 70 miles away!) In the late 1960s a small opening above the main doorway was uncovered. It was then discovered that if there is sunlight on the 21st December (the shortest day of the year) the chamber will light up for about 17 minutes making it one of the oldest accurate time clocks in the World. Anyone visiting this incredible monument can experience an approximation of the phenomenon any time of year by electric light and is often the highlight of the tour. A lottery is held annually for ‘tickets’ to allow the lucky holder into the tomb to view the actual event.