Bid to solve mystery of swan glyph found on kerbstone at 5,500-year-old Irish passage mound
Discovery at Knowth links the Boyne Valley to ‘swan and sunrise’ winter solstice motifs found in ancient cultures worldwide

Irish-American writer and journalist Ben Gagnon made an extraordinary discovery about Ireland’s distant past while working on a new book.

Earlier this year, Ben, from Cambridge, Massachusetts, whose forebears lived in the south-west of Ireland, was reviewing some photographs he’d taken at the prehistoric passage mound at Knowth in Co Meath.
Knowth and its neighbouring mounds of Newgrange and Dowth — the ancient ‘cathedrals’ of Ireland — were built more than 5,000 years ago, making them older than England’s Stonehenge. Built by farming peoples, the mounds, or passage tombs as they are also called, have clear astronomical alignments, for example, to the winter solstice sunrise.

The Knowth mound is notable for the 124 surviving kerbstones around its base. And on one of these that Ben had photographed, he noticed a horizontal stain running just below the top and wondered if the stone had once been set in soil or shallow water and later inverted.
He flipped the photo and was astounded to see something no one had ever seen before — the faint but unmistakable image of a swan in profile. The swan was looking at what appeared to Ben to be the image of a rising sun, a carving which, on this stone — catalogued K-15 by archaeologists — has been said to be the world’s oldest sundial.

But Ben knew that both the swan and rising sun images resonated strongly in the Boyne Valley where, for millennia, whooper swans from Iceland have over-wintered — the book he’s writing is about the significance of birds to ancient societies — and that Newgrange was designed to celebrate the winter solstice when rays of the rising sun enter a ‘roofbox’ over the entrance and illuminate the inner chamber.
Crucially, Ben thinks the swan image calls into question the interpretation of K-15 as a sundial, a conclusion drawn by Martin Brennan, the Irish-American author of books about the art and astronomy of prehistoric Ireland.
Ben told me: ‘Mr Brennan’s extensive work on K-15 doesn’t mention the stone being turned upside-down in the distant past, placing in question the credibility of his tests and conclusions.’
But why might the kerbstone have been turned upside-down?
Ben said: ‘Archaeologists studying the ritual abandonment of sacred sites have found that when ancient cultures suffered a plague or some other catastrophe, they often relocated the entire community. Turning the Knowth kerbstone upside down may have been an attempt to hide its secrets and/or extinguish its spiritual power as part of the ritual abandonment process. If the idea was to hide the stone’s secrets, it worked quite well for a very long time.’
While potentially answering some questions about the use of K-15, the discovery of the swan and rising sun images have created a new mystery which Ben hopes to solve.
Naturalistic art
For the two images are the only examples of naturalistic art in the entire Boyne Valley. The neolithic art at Knowth, Dowth and Newgrange is dominated by spirals, circles, diamond-shapes, wavy lines and other geometric figures — there are no other natural forms.
While it was possible K-15 was carved when the mound at Knowth was built more than 5,000 years ago, said Ben, the two naturalistic images suggested it might have been created by a culture that arrived after the mound was abandoned by its builders. If so, the leading candidate would be the Celts, who adopted the mounds of the Boyne Valley into their mythological world.
The swan and rising sun images resonate in Celtic culture generally and the Boyne Valley specifically, including a shape-shifting love story in which the legendary Angus falls for a swan-maiden and turns himself into a swan to be with her. Also, the flag carried by the law enforcement arm of pre-St Patrick Ireland — the Fiana — was a rising sun.

Ben has identified the swan and rising sun images as a motif of the winter solstice found in eight other ancient cultures over a 4,000-year period. The symbolic motif was a time-stamp based on the relative positions of the constellations Cygnus the swan and Draco the dragon at the time of the winter solstice (see star map, left).
In a dozen examples Ben has identified, a variety of birds stand in for Cygnus at left, including two swans, an eagle, a vulture, an owl and a dove. The upside-down U-shapes that represent the Draco constellation, at right, include snakes, a dragon, rivers, a headdress, a veil, a hat — and the semicircular rising sun at Knowth.

The motif can be found, for example, at the 2,000-year-old Ara Pacis altar of Ancient Rome, on the Celtic Gundestrup cauldron dating from about 1BC, in the 3,500-year-old tomb of Nebanum, a government accountant in Ancient Egypt, on an Akkadian cylinder seal from about 2,250BC, in a third century votive relief of the Roman Jupiter, in an early Armenian Christian carving of Jesus Christ, and an Aztec Codex depicting a human sacrifice to the sun god Huitzilopochtli at the winter solstice.

So while it appears K-15 was part of a winter solstice celebration, it remains unclear exactly how the kerbstone was used, said Ben. He believes a test of the horizontal stain on K-15 could confirm that it was once set in a shallow pool.
About 4,000 years ago, the druids of Britain and Ireland practised divination by staring into polished beryl, quartz, black glass or images in still water, according to accounts from Julius Caesar and the Roman writer Pliny. In ancient cultures, the winter solstice was celebrated as New Year’s Day — a perfect day to make predictions for the coming year.

If the swan and rising sun images on K-15 were intended to be viewed in a shallow reflecting pool, the swan would have appeared as Cygnus at left with the U-shape of Draco, suggested by the semi-circular rising sun, at right, in the same relative positions as the constellations in the night sky.
If the divination ritual took place at dawn, the practitioners could have placed polished quartz in the inset cupules, or sockets, at the centre of the rising sun glyph, causing the rays of the rising sun to refract the colours of the rainbow over the image in the pool.
‘More analysis of K-15 would help settle these questions,’ said Ben. ‘Was the horizontal stain caused by immersion in water? How old is the stone? Are there crystal remnants in the cupules? Where was K-15 first found? It’s time for a new look. The possibility of Celtic origin is intriguing to say the least.’
Research for a novel
Ben visited the Boyne Valley as part of research for a novel, in which characters explore Ireland’s ancient megalithic mounds, due to be published this autumn.
He has traced the Harrington side of his family to the townland of Disert, just outside Castletownbere on the Beara peninsula, Co Cork. Parish records suggest an entire branch of the Harrington family fled the Irish famine by emigrating in 1848 to Portland, Maine. Much of the family worked in the granite quarries and textile mills in eastern Massachusetts, and at least one member of it fought in the American Civil War.
The tradition at the time for many Irish immigrants in New England was to fully embrace being American, said Ben, who counts among his ancestors names such as Patrick Henry Harrington and Noah Webster Harrington.
