From December 19 to 23 — if the weather cooperates — 20 lucky people a day will crowd into an ancient Irish monument's main chamber. There, they'll bathe in 17 minutes of light put off by the rising sun on the shortest days of the year. This year about 28,000 people applied to take part in the ritual at the Newgrange monument, located in the Irish countryside in County Meath, reports the Brú na Bóinne Visitor Center.
     According to Edwin Krupp, director of the Griffith Observatory in Los Angeles, California, the monument incorporates knowledge that could only have been gained through precise astronomical observations. "The people who built it knew about the winter solstice — knew when it occurred, knew where the sun would rise — and built a monument that took advantage of that event and incorporated it symbolically into the monument," he said.
     The 62-foot-long (19-meter-long) passage faces the winter solstice sunrise. A little window above the door allows light from the rising solstice sun to reach the depths of the burial chamber from about 8:58 a.m. to 9:15 a.m. local time.
     Newgrange is the most elaborate of several passage tombs in the rich agricultural lands along the Boyne River about 30 miles (50 kilometers) north of Dublin. The number of area monuments "suggests this wasn't a small rural community of a few farmers and herders," Krupp said. "We're seeing something there certainly bordering on chiefdomship, if not actually a chiefdomship." According to Krupp, the full story behind the purpose of Newgrange and its kin is still shrouded in mystery. "We don't have an owner's manual, and there is no writing," he noted.
     However, archaeologists have pieced together some of the story. "It is very deliberately designed and constructed to capture the light of the rising sun at the winter solstice, to allow that beam of light to fall on the innermost chambers of it—a place where in fact the remains of the honored dead were incorporated," Krupp said. Scratch marks in the window above the door indicate that rocks were repeatedly removed and put in place to open and close the window, suggesting a regular gathering at the monument for a winter solstice ritual. "The winter solstice is a crucial moment, in that it marks the time the sun has reached the depths of winter—its darkest moment, its death, and its rebirth," Krupp added.
     Today as many as 200,000 people a year come to visit Newgrange, making it the most visited archaeological site in Ireland. Access to the monument is controlled by the Brú na Bóinne Visitor Center. The solstice is the most sought-after time to visit the monument. So in 2000 the visitor center switched to a lottery system for tickets, deeming luck-of-the-draw fairer than a ten-year-long wait list. Schoolchildren pick the winners in late September or early October. For five days around the winter solstice, 20 people a day are granted access to the chamber at sunrise. And on the day of the actual winter solstice—usually December 21—several hundred people also gather outside Newgrange to watch the sunrise.

Source: National Geographic News (7 December 2006)