<strong>Newgrange:</strong> Ireland's Newgrange passage tomb is one of the earliest and greatest feats of solar alignment, built 500 years before the Giza pyramids and 1,000 years before Stonehenge.
Newgrange: Ireland's Newgrange passage tomb is one of the earliest and greatest feats of solar alignment, built 500 years before the Giza pyramids and 1,000 years before Stonehenge.
Tourism Ireland
<strong>Winter Solstice:</strong> Each year, between December 19 and 23, hundreds gather at dawn at this prehistoric tomb. A lucky few will have won entry by lottery -- in 2016 just one in 545 applicants got the chance.
Winter Solstice: Each year, between December 19 and 23, hundreds gather at dawn at this prehistoric tomb. A lucky few will have won entry by lottery -- in 2016 just one in 545 applicants got the chance.
Brian Lynch/Tourism Ireland
<strong>Dawn's early light: </strong>Shortly before 9 a.m., light strikes through the "roofbox" above the tomb's entrance, creeping along the passageway and eventually flooding the innermost chamber with light.
Dawn's early light: Shortly before 9 a.m., light strikes through the "roofbox" above the tomb's entrance, creeping along the passageway and eventually flooding the innermost chamber with light.
Brian Lynch/Tourism Ireland
<strong>Megalithic art:</strong> Newgrange is part of the Brú na Bóinne World Heritage Site. UNESCO has described it as "Europe's largest and most important concentration of prehistoric megalithic art."
Megalithic art: Newgrange is part of the Brú na Bóinne World Heritage Site. UNESCO has described it as "Europe's largest and most important concentration of prehistoric megalithic art."
Brian Morrison/Tourism Ireland
<strong>Burial chamber: </strong>"The remains that they find in the passage tombs are generally cremated," says Clare Tuffy, manager of Brú na Bóinne Visitor Centre. "But they can identify that the remains are from adults and children, male and female. We imagine they were families of very high status, or families that perhaps had a direct link to the ancestors who founded the Boyne Valley."
Burial chamber: "The remains that they find in the passage tombs are generally cremated," says Clare Tuffy, manager of Brú na Bóinne Visitor Centre. "But they can identify that the remains are from adults and children, male and female. We imagine they were families of very high status, or families that perhaps had a direct link to the ancestors who founded the Boyne Valley."
Brian Lynch/Tourism Ireland
<strong>Dowth: </strong>There are three large burial mounds at Brú na Bóinne -- Newgrange, Knowth and Dowth -- and around 40 satellite passage graves.
Dowth: There are three large burial mounds at Brú na Bóinne -- Newgrange, Knowth and Dowth -- and around 40 satellite passage graves.
Failte Ireland
<strong>Knowth: </strong>The Newgrange site is filled with purely prehistoric artifacts, but the site at Knowth was used again and again until the Anglo-Norman period.
Knowth: The Newgrange site is filled with purely prehistoric artifacts, but the site at Knowth was used again and again until the Anglo-Norman period.
Tony Pleavin/Tourism Ireland
<strong>Gavrinis, France: </strong>Communal passage tombs proliferated across western Europe in the Neolithic era. Examples today include Gavrinis in France (pictured), Maeshowe in Scotland and Bryn Celli Ddu in Wales.
Gavrinis, France: Communal passage tombs proliferated across western Europe in the Neolithic era. Examples today include Gavrinis in France (pictured), Maeshowe in Scotland and Bryn Celli Ddu in Wales.
MIGUEL MEDINA/AFP/Getty Images
<strong>Hill of Tara:</strong> The Hill of Tara archaeological complex, ancient seat of the High Kings of Ireland and used from the Neolithic period to the 12th century, is a short distance away beside the River Boyne and can be combined with a day trip to Brú na Bóinne.
Hill of Tara: The Hill of Tara archaeological complex, ancient seat of the High Kings of Ireland and used from the Neolithic period to the 12th century, is a short distance away beside the River Boyne and can be combined with a day trip to Brú na Bóinne.
Tourism Ireland
<strong>Ireland's Ancient East: </strong> Brú na Bóinne is a key landmark in what the country's tourism board has called Ireland's Ancient East. Other highlights include the sixth-century monastic site of Glendalough, south of Dublin in County Wicklow.
Ireland's Ancient East: Brú na Bóinne is a key landmark in what the country's tourism board has called Ireland's Ancient East. Other highlights include the sixth-century monastic site of Glendalough, south of Dublin in County Wicklow.
Tourism Ireland
<strong>Monasterboice:</strong> A little north of the River Boyne lies the early Christian settlement of Monasterboice, home to the oldest known Celtic cross.
Monasterboice: A little north of the River Boyne lies the early Christian settlement of Monasterboice, home to the oldest known Celtic cross.
Tony Hill Photographic
<strong>Ancient connection:</strong> "There are very few experiences that you can share across five millennia, with your ancestors," says Tuffy. "It's very heartwarming and inspiring."
Ancient connection: "There are very few experiences that you can share across five millennia, with your ancestors," says Tuffy. "It's very heartwarming and inspiring."
Brian Morrison/Tourism Ireland