Newgrange is regarded by prehistorians and archaeologists as one of the greatest national monuments of Ireland and as one of the most important megalithic structures in Europe built during the Neolithic period around 3200 BC, therefore making it older than Stonehenge and even the Egyptian pyramids. The large mound is approximately 85 metres wide at its widest point and is surrounded at its base by a kerb of 97 stones, it consists of approximately 200,000 tonnes of rock and other materials; the most impressive of these stones is the highly decorated Entrance Stone. The mound has a retaining wall at the front, made mostly of white quartz cobblestones, and is ringed by engraved kerbstones. Many of the larger stones of Newgrange are covered in megalithic art. The site consists of a large circular mound with an inner stone passageway and chambers. Human bones and possible grave goods or votive offerings were found in these chambers. it is believed that it had religious significance because its entrance is aligned with the rising sun on the winter solstice when sunlight shines through a 'roofbox' and floods the inner chamber similar to several other passage tombs in Ireland which are also aligned with solstices and equinoxes. Newgrange is the most famous monument within the prehistoric landscapes dating from the Neolithic period and is a UNESCO World Heritage Site.