As the sun rises higher, the projected beam moves lower and lower across the back stone, though it never loses its intensity. The warm, orange glow of sunrise begins to fade and the paler light now highlights what is considered a universal symbol of the sun.

The light now starts to cross onto the orthostats of the main chamber and will shortly begin its retreat down the right hand side of the passage.

Towards the end of the event, the floor of the passage is illuminted but does not cross the floor of the main chamber as at Newgrange, a curved-top sillstone blocks this late light from hitting the chamber floor.

The exterior of Cairn T, viewed from the ruinous chamber of Cairn V.

The spectacle is over for today, the climb to the hilltop in the freezing darkness has been worth it and the small crowd leaves in good humour.

For some, this was their first experience of this piece of stone-age theatre and for others it will be another fine morning to recall of the many. But each year, more and more people gather on this hilltop at the time of equal day and night ensuring that despite the constant weathering and ruination of these magnificent temples, a measure of appreciation and wonderment for these ancient achievements endures over 5,000 years later.