The passage and chamber of Newgrange are illuminated by the winter solstice sunrise. A shaft of sunlight shines through the roof box over the entrance and penetrates the passage to light up the chamber. The dramatic event lasts for 17 minutes at dawn on the Winter Solstice and for a few mornings either side of the Winter Solstice.
The Megalithic Passage Tomb at Newgrange was built about 3200 BC. The kidney shaped mound covers an area of over one acre and is surrounded by 97 kerbstones, some of which are richly decorated with megalithic art. The 19 meter long inner passage leads to a cruciform chamber with a corbelled roof. It is estimated that the construction of the Passage Tomb at Newgrange would have taken a work force of 300 at least 20 years.