Robin Hood and Little John 2
Image by Chris Collyer

>As a side note: Apparently you need modern surveying equipment to differentiate between the sun's position for the four days either side of the Solstice, so the alignment of the passage could have easily been done by eye and not through any special advanced maths or astronomical calculations<

sorry 4Ws, did you mean "you DON'T need modern surveying equipment" in that paragraph, or am I misunderstanding something?

Squid

Ok. You *do* need modern surveying equipment to see the difference over this period. So basically the sun rises in the same place (to the human eye) for nine days. i.e. there is no 'one moment' that Newgrange is aligned with, but an event at the same place at the same time on nine consecutive days around the Winter Solstice.