A 5,000-year-old tomb only lights up once a year

Older than the Pyramids of Giza, the Newgrange monument is a 250,000-ton masterpiece of ancient astronomy. For 364 days a year, the inner sanctum remains in total darkness. However, at precisely 8:58 AM on the winter solstice, the rising sun aligns with a small opening known as the 'roofbox.' A blade of light shoots 19 meters down a long stone passage, hitting the floor of the central chamber and illuminating the intricate triple-spiral carvings on the back wall.