Ruins of the megalithic cairn near the summit of Tibradden, Dublin Mountains, Ireland. Enlarge photo.

origin of the Global Vision project:

Michael O'Callaghan conceived the Global Vision project on the Summer Solstice 1972, during an astro-archaeological field trip to the ancient ruined megalithic cairn at Tibradden in the Dublin Mountains, Ireland (see photo above). Every year on this date, the cairn's passage appears to become aligned to the position of the sun's first appearance as it rises, beyond Dublin Bay, over the horizon of the Irish Sea.

This cairn is known locally as Nial Du's grave, and is mentionned by Robert Graves in his book The White Goddess, and by Samuel Beckett. Nial Du is mentioned by James Joyce in his Finnegans Wake.

The cairn was badly damaged during archaeological excavations by the Royal Irish Academy in 1849. They removed the centre of the cairn to expose the central chamber (visible in the photo above), where they discovered a burial urn which is now conserved at the National Museum in Dublin. They then failed to replace the stones which constituted the roof of the central chamber.

Archaeologists first classified this monument as an early Bronze Age "passage grave" or "passage mound", but later changed its classification to "cairn", claiming the passage (visible in the photo above) is mere artifact of the earlier excavation work. However, the fact that the passage is aligned to the summer solstice sunrise suggests the monument may well date to the Neolithic period, around 4,000 - 3,000 BCE.

Many Irish megalithic sites from the Paleolithic and Neolithic periods, such as Newgrange and other monuments in the Boyne Valley UNESCO World Heritage site, include passages, petroglyphs, and gnomons aligned to locally visible positions of the sun, moon and stars at Solstices, Equinoxes and other astronomically significant dates. The oldest of them were built by the pre-Indo-European indigenous people known as the Tuatha Dé Danaan - People of the Goddess Danu.

Unfortunately Irish archaeologists frequently ignore or downplay the significance of these astronomical design features, and occasionally damage them during "renovation". The most famous example of such unintended archaeological vandalism occured in 2000 in the Boyne Valley complex at the 5,500 year-old great chambered passage mound at Knowth - Europe's most richly decorated and one of the largest chambered passage mounds surviving from Neolithic times, which the Guardian newspaper described as being of "immense historical significance." The so-called "restoration" of this cairn included blocking its 36-meter Eastern passage with a slab of concrete, claiming it has no astronomical significance. Not only does this sabotage the architectural, artistic and astronomical integrity of the monument, but it also precludes any further observation and research on the illumination of the passage by the sunbeam which would otherwise enter it at dawn around the Spring Equinox.

Further research may hopefully clarify the date of the cairn on Tibradden, and the construction of its passage.

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URL of this page: www.global-vision.org/about/tibradden.php • updated 26 June 2010