Newgrange, Co. Meath

Built around 3,200 BC. Five hundred years older than the Great Pyramids. A thousand years older than Stonehenge. For seventeen minutes each year, on the mornings around the winter solstice, the rising sun threads through a roof-box above the entrance and floods the inner chamber with light. The farmers who built it spent thirty years aligning a passage tomb to a sunrise they could not predict in advance. They were correct.