Newgrange was hidden for thousands of years within a great mound. Newgrange is a very popular and spectacular tomb in Ireland. It is a megalithic tomb. It was built around 2500 BC. The tomb consists of a passage and burial chamber, covered by a circular mound and surrounded by a kerb of large stones.
The passage leads to a central chamber out of which open three
side chambers. The stone roof of the burial chamber at Newgrange is known as a corbelled roof. It is made by placing closely fitting slabs one on top of the other. Itís like building a roof with Lego.
On the 21st of December each year the sunís rays shine through the roof box and the passage and light up the burial chamber in the centre of the tomb. All during the year the room in the centre of the tomb is in darkness. To get to this room you have to walk up the passage from the entrance of the tomb. At the winter solstice the sun comes shining into the passage and its rays reach the room in the centre of the Mound. These rays light up the whole room.
Lots of visitors visit Newgrange every day. Now there are electric lights in the passage and the room. When all the visitors are in the room the lights are turned off and the guide explains what happens on the 21st of December. They explain that as the sun rises the rays shine through the roof box and start to move up the tunnel. After approximately 20 minutes the rays hit the back wall in the central room. The room is then quite bright. As the sun rises higher in the morning sky the rays go back down the passage and the room is left in darkness for another year. While you are listening to the guide they also have a light doing the same job as the sun would do. This is called a simulation of the winter solstice. It is very spectacular. You can see the light coming up the passage towards you and the room lighting up and then the light disappearing down the passage again just as would happen if the sun were really rising.
There are carvings on the rocks and the sun during the winter solstice illuminates these. Martin Brennan studied the design in the stones for two and a half years and decided that they represented the ancients understanding of the sun and the stars.