Loughcrew Equinox

On the mornings around the Spring Equinox and the Autumn Equinox on Carnbane East at Loughcrew, the rising sun illuminates the passage and chamber of Cairn T. The sun light is shaped by the stones of the entrance and passage and descends the backstone while moving from left to the right illuminating the solar symbols.


The equinox illumination of Loughcrew Cairn T is a remarkable phenomenon where sunlight aligns with the passage and chamber of the ancient megalithic structure during the equinox. Specifically designed to capture this celestial event, Cairn T at Loughcrew becomes illuminated as the sun rises, casting light down the passage and into the chamber.

The precision in the construction of Cairn T allows for this captivating play of light and shadow during the equinox, creating a stunning spectacle that underscores the ancient builders' astronomical knowledge and architectural expertise. The event serves as a testament to the alignment of ancient structures with celestial events, possibly having symbolic or ritualistic significance for the people who constructed and used these monuments.

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.