Loughcrew Video - Spring Equinox 2005

The progress of the sunbeam on the backstone inside Cairn T at Loughcrew was video recorded at sunrise on the morning of March 23rd 2005. The 50 minute video has been compressed to 1 minute 46 seconds and included in the following YouTube Video.

At the spring and autumn equinoxes, the rising sun can shine straight along the passage of Cairn T on Carnbane East and into its cruciform chamber. For roughly fifty minutes at dawn, a narrow beam moves across the decorated backstone, bringing out carvings that are easy to miss in ordinary light. The effect is less famous than the winter solstice at Newgrange, but it ranks among the clearest prehistoric solar alignments in Ireland.

The backstone is one of the richest panels of passage tomb art in the country, covered with concentric circles, radiating lines and other abstract motifs whose original meaning remains uncertain. As sunlight advances across the stone, the engraved surface seems to shift and sharpen, suggesting that the builders not only buried the dead here but staged a timed encounter between sky, stone and community at the turning points of the year.

The modern recognition of the Cairn T equinox alignment is associated with Martin Brennan and Jack Roberts, who documented the phenomenon in 1980. Brennan discussed the discovery in The Stones of Time, drawing fresh attention to Loughcrew and encouraging further study of Ireland's passage tombs. While debate continues over some of his wider interpretations, the equinox illumination itself is now well established among archaeologists and visitors alike.

Loughcrew, or Sliabh na Caillíghe, spreads across several hilltops near Oldcastle in County Meath, with more than thirty passage tombs surviving in various states of preservation. Cairn T crowns Carnbane East and is surrounded by smaller satellite tombs; the Hag's Chair, a massive kerbstone with armrest-like projections, stands on the northern side of the mound. Local folklore long associated the hills with the Cailleach, the hag who in legend dropped cairns of stones as she leaped from peak to peak.

Equinox mornings are unpredictable. Cloud, mist or rain can hide the beam entirely, as visitors found during the 2008 and 2009 dawns, when brief clear intervals produced memorable photographs on some days and disappointment on others. That uncertainty is part of the experience, and it helps explain why people still gather on the hillside in hope of seeing light meet art as it did five thousand years ago. With Cairn T closed for conservation in 2019, the chamber could not be entered, yet the hillside assembly remained a way to mark the equinox at one of Ireland's great Neolithic cemeteries.