Newgrange

Newgrange was built around 3200 BC, making it five centuries older than the Great Pyramid of Giza and a thousand years older than Stonehenge. Its passage and chamber were aligned with such precision that once a year, at the winter solstice, the rising sun shines directly down the 19-metre passage and illuminates the inner chamber for approximately seventeen minutes — flooding with light a space that is otherwise in complete darkness. The builders achieved this without instruments, without metal tools, and without the wheel.

In Irish mythology, Newgrange — Brú na Bóinne, the Palace of the Boyne — is the home of the Dagda, the father-god, and later of his son Aengus Óg, the god of love and youth. The myth of how Aengus came to possess it is one of the most elegant in the cycle: he asked his father for the brú for a day and a night. When the Dagda tried to take it back, Aengus pointed out that all time is composed of a day and a night — and so he holds it still.

Newgrange continued to be a sacred site through the Bronze Age, Iron Age, and into the early Christian period. It was known to the people of every age who came after its builders, who interpreted it according to their own cosmologies. The winter solstice sunrise it was built to capture is still observed today; the chamber is open to those who win the annual lottery draw, and thousands more watch the event streamed live.