Newgrange Winter Solstice
On the days around the Winter Solstice when the skies are clear the rising sun
illuminates the passage and chamber of the 5000 year old megalithic passage tomb
at Newgrange in the Boyne Valley.
Above the entrance to the passage of the mound there is a opening called a roof-box.
On mornings around the winter solstice a beam of light penetrates the roof-box and
travels up the 19 metre (63 ft) passage and into the chamber. As the sun rises higher,
the beam widens so that the whole chamber is dramatically illuminated.
The rising sun.
Solstice Sunbeam in the Newgrange passage.
The white quartz glows in the sunlight at Newgrange.
A perfect sunrise to illuminate the passage and chamber at Newgrange.
The solstice lottery winners were experiencing a wonderful sunrise in the
Newgrange chamber while the people outside waited patiently for their turn to
enter the chamber.
The sunbeam retreating from the passage at Newgrange.
On the mornings around the Winter Solstice the rising sun shines directly along the long passage
into the chamber for about 17 minutes and illuminates the chamber floor. Professor
Michael J. O'Kelly was the first person in modern times to observe this event on
21st December 1967. The sun enters the passage through a specially contrived opening,
known as a roofbox, directly above the main entrance. Although solar alignments are
not uncommon among passage graves, Newgrange is one of few to contain the additional roofbox feature.
The alignment is such that although the roofbox is above the passage entrance, the light
hits the floor of the inner chamber. Today the first light enters about four minutes
after sunrise, but calculations based on the precession of the Earth show that 5,000
years ago first light would have entered exactly at sunrise. The solar alignment at
Newgrange is very precise compared to similar phenomena at other passage graves such
as Dowth or Maes Howe in the Orkney Islands, off the coast of Scotland.