The winter solstice at the Newgrange passage tomb in Co Meath was broadcast live on the internet this morning although many people were unable to view the streaming video on the Heritage Ireland website as it struggled to cope with the heavy traffic.
Today's live stream began at 8.30am today, and the phenomenon will be broadcast at the same time tomorrow on the Heritage Ireland website.
Light streams into the chamber every year as the sun rises after the longest night of the year.
Thousands apply annually for permission to witness the first rays of light creep through the ancient monument, but only a handful are allowed access to the structure's main chamber.
Newgrange, one of the finest passage tombs in Western Europe, is believed to date from around 3,200 BC, making it 500 years older than the Great Pyramid of Giza in Egypt and a thousand years older than England's Stonehenge.
Archaeologists believe the grass-covered mound is a "passage tomb," with a passage running to a cave-like chamber, where the remains of the dead were placed.
