Newgrange is by far the most famous of all Ireland’s ancient monuments. It is part of a complex of over 35 similar type monuments built along a bend of the River Boyne which is known collectively as Brú na Bóinne. It was built around 2700 BC and is classified as a UNESCO World Heritage Site. 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 was 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 inner passage is 40-feet long and 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 quartz from the Wicklow Mountains from 70 miles away! In the late 1960s, a small opening above the main doorway was uncovered and it was discovered that 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.