Around 200 people have gathered around the ancient passage tomb at Newgrange, Co Meath, to mark the Winter Solstice.
A narrow beam of sunlight broke through the opening known as the roof box and lit up the chamber of the 5,000-year-old tomb at 8.56am.
It is the first time in six years that the light entered the chamber.
Built 1,000 years before the Great Pyramids of Giza, the passage tomb at Newgrange was designed and constructed by Stone Age man.
A number of other events are taking place around the country to mark the shortest day of the year.
At one of them, South Kilkenny Historical Society gathered for the Winter Solstice at the Knockroe passage tomb in the county.