It's 500 years older than the Great Pyramid of Giza, features a chamber of mind-boggling astronomical precision, and recently yielded a DNA discovery straight out of Game of Thrones. Newgrange, a passage tomb in County Meath, Ireland, is one of the most remarkable structures of the ancient world.

This episode strips away assumptions about cavemen to explore the engineering genius behind this Neolithic monument. We examine how Anatolian-descended farmers moved 200,000 tons of material without wheels or metal, the solstice light that pierces the chamber, and the fierce debates over its meaning and its controversial modern restoration.

• How builders transported multi-ton stones up to 50 km using tidal mechanics and water displacement along the river Boyne
• The roof box that channels a beam of solstice sunrise light 19 meters d ...