Irish Myths is reader-supported. When you buy through links on our site, we may earn a small affiliate commission.
For thousands of years, it lay in waiting, submerged completely at high tide and so thick with seaweed that even at low tide, it was mostly hidden.
Mostly.
The locals living near Clew Bay (Cuan Mó) knew.
Or rather, they knew about part of it: a curved and clearly human-made structure on Collanmore Island.
But as to the structure’s age and significance, the locals were at a loss.
Then, in March of 2024, archaeologist Michael Gibbons made a discovery. Turns out, the structure was the outer rampart of a Bronze Age fort dating to between 1100 and 900 BCE.
To quote journalist Lorna Siggins, writing for the Irish Independent:
“The first clue appeared when several large ramparts were uncovered cutting across the tidal isthmus linking the island to the shoreline outside Westport. Collanmore, which is accessible by foot at very low tides, was once a base for the Glenans Irish Sailing Club. The set of double ramparts are faced with large limestone blocks and extend for 200 to 300 metres.”
According to Gibbons, he happened to be in the area with a team from Connemara as well as archaeologists from Mayo County Council when he noticed people cutting seaweed, revealing the large limestone blocks on the face of the outer rampart.
“These ramparts will have controlled access to the island from people coming from the mainland,” Gibbons told the Irish Independent. The size and scale of the ramparts, he continued, “would suggest that the island was of major strategic importance at the time.”
Similar Bronze Age stone forts can be found at several other coastal and lakeside locations in the west of Ireland, including at Lough Fee, Lough Carra, and, perhaps most famously, at Inis Mór, home of Dún Aonghasa (a.k.a. Dún Aengus), which sits on the edge of a 100-meter-high (330-foot-tall) cliff.
We’ll revisit Dún Aonghasa in a minute—it still has a role to play in this story yet.
But first, let’s turn our attention back to Clew Bay and its curious connections to Irish mythology.
Clew Bay: Home of the Fir Bolg?
The Fir Bolg are the fourth of six mythical races to settle in Ireland as detailed in the Lebor Gabála Érenn (The Book of the Taking of Ireland). They are preceded by the Cessair, the Partholónians, and the Nemedians, and are followed by the Tuatha Dé Danann (the Irish gods) and the Milesians (who are thought to represent the Gaelic-speaking Celts).
Descendants of the aforementioned Nemedians, who are forced to leave Ireland “courtesy” of the marauding Fomorians, the Fir Bolg or “men of bags” earn their name while enslaved by the Greeks, during which time they are forced to carry around bags of earth.
Anyway, it is the Fir Bolg who establish the High Kingship in Ireland, setting the seat of royal power in Tara. They rule Ireland for 37 years, after which point the Tuatha Dé Danann arrive and kick their butts during the First Battle of Mag Tuired.
But the Tuatha Dé Danann are not totally merciless, as they eventually allow the surviving Fir Bolg—specifically, the sons of Umor—to resettle in Connacht.
The Fir Bolg king Aonghus mac Úmhór, for example, “constructed the fortress of Dun Aonghusa on the island of Aran Mor in Galway Bay,” to quote from Harry Mountain’s The Celtic Encyclopedia. (See, I told you Dún Aonghasa would pop up again!)
Umor’s son Mod, meanwhile, “settled his people on Modlind.”
And here’s where the Fir Bolg fort theory really starts to come together, because historically, Clew Bay was known as—you guessed it—Modlind, meaning “pool of Mod.” It was also called Cuan Mod (“harbor of Mod”), which is why today Clew Bay is known as Cuan Mó in Irish.
But it’s not just the bay that is referenced in Irish mythology; the islands in the bay, referred to as Insi Mod, are also referenced specifically. To quote from Whitley Stokes’ translation of the Bodleian Dinnshenchas (a.k.a. Dindshenchas, meaning “lore of places”):
“The hounds of Manannan mac Lir and the hounds of Mod, from
whom Insi Mod are named, met together around the pig that
devastated the land about them, even Insi Mod.”
Yeah, so apparently an evil pig laid waste to the Clew Bay Islands…and perhaps destroyed a certain stone fort in the process?
Okay, fine, I’m stretching. But the Dindshenchas definitely hints at the mythological significance of Clew Bay and its islands, a significance that is also apparent in the events preceding the Second Battle of Mag Tuired.
During this time, Bres—the half-Fomorian ruler of the Tuatha Dé Danann who was chosen to replace the maimed Nuada of the Silver Hand—is acting like a big old jerk. Bres forces Ogma, champion of the Tuatha Dé Danann and (mythical) inventor of the Ogham alphabet, to complete menial, repetitive tasks. As detailed in by Elizabeth A. Gray’s translation of the Cath Maige Tuired:
“This was the duty which he [Ogma] had, to bring firewood to the fortress. He would bring a bundle every day from the islands of Clew Bay. The sea would carry off two-thirds of his bundle because he was weak for lack of food. He used to bring back only one third, and he supplied the host from day to day.”
Was Ogma, in essence, collecting the firewood from the Fir Bolg living on the Clew Bay Islands to give to Bres as tribute?
It’s unclear.
But what is clear is that the islands remain associated with the Fir Bolg even when we advance in time from the era of pure Irish mythology (re: the Mythological Cycle) into the era of Irish legend and quasi-history (re: the King Cycle).
Specifically, during the Battle of Mag Mucrama (“the plain of the counting of the pigs”—guess where that name came from?), Lugaid mac Con, who had been exiled in Alba (re: Scotland), returns to Ireland “with an army of Britons,” to quote from Thomas Francis O’Rahilly’s Early Irish History and Mythology.
Mac Con then takes possession of “the islands in Clew Bay (Insi Mod).”
In a footnote, O’Rahilly provides the following theory as to why our favorite islands get name-dropped in this quasi-historical tale:
“A possible reason for mentioning these islands is that elsewhere Clew Bay is said to have been occupied by the Fir Bolg (cf. Modlind, i.e. ‘ Cuan Mod ’, Clew Bay…).”
The Fort That Inspired the Fir Bolg
While there are no direct references to a fort in Clew Bay in the Irish myths and legends, I think it’s safe to say that the presence of such a fort can be inferred. Hence, the constant battling. Whoever controlled the fort on the Clew Bay Islands controlled the bay.
But to put on my historian hat for a second, it’s clear that the Fir Bolg didn’t build the fort; they’re a mythical people. Instead, the fort likely inspired stories about the Fir Bolg.
Think about it: the coastal and lakeside forts that dot western Ireland were built in the Bronze Age—most likely by the Bell Beaker people. Those are the folks who settled in Ireland before the ancient Gaelic-speaking Celts but after the Stone Age builders of monuments like Newgrange in the Boyne Valley.
The Bell Beaker people were named for their distinctive, inverted bell-shaped pottery, but were also master metallurgists, crafting weapons, tools, and even musical instruments from bronze.
And while it is the Celts who are often credited with ushering in Ireland’s Iron Age, the Bell Beaker people had already started working with iron prior to their arrival.
Which makes this passage from O’Rahilly’s Early Irish History and Mythology all the more interesting:
“Worth noting, perhaps, is a statement in L. G. to the effect that it was in the time of Rinnal, king of the Fir Bolg, that weapons were first provided with points, i.e. with iron heads ; previously only wooden shafts had been used. Possibly this represents a genuine tradition that iron weapons were first introduced by the Fir Bolg.”
So now all of the pieces have fallen into place.
When the Gaelic-speaking Celts arrived in Ireland, they either encountered the Bell Beaker people directly, with their iron-tipped spears and their coastal and lakeside stone forts, or they discovered the remnants of those artifacts and structures. Either way, the Celts made up stories about these earlier Irish settlers, dubbing them the Fir Bolg and placing them in the very same locations where the real-life Bell Beaker people once dwelt.
Places like the recently re-discovered stone fort in Clew Bay.
P.S. Interested in Celtic culture? Check out…
Samhain in Your Pocket
Perhaps the most important holiday on the ancient Celtic calendar, Samhain marks the end of summer and the beginning of a new pastoral year. It is a liminal time—a time when the forces of light and darkness, warmth and cold, growth and blight, are in conflict. A time when the barrier between the land of the living and the land of the dead is at its thinnest. A time when all manner of spirits and demons are wont to cross over from the Celtic Otherworld. Learn more…
Neon Druid: An Anthology of Urban Celtic Fantasy
“A thrilling romp through pubs, mythology, and alleyways. NEON DRUID is such a fun, pulpy anthology of stories that embody Celtic fantasy and myth,” (Pyles of Books). Cross over into a world where the mischievous gods, goddesses, monsters, and heroes of Celtic mythology live among us, intermingling with unsuspecting mortals and stirring up mayhem in cities and towns on both sides of the Atlantic, from Limerick and Edinburgh to Montreal and Boston. Learn more…
Audio-visual learner? Check out the IrishMyths YouTube Channel:
More the listenin’ type?
I recommend the audiobook Celtic Mythology: Tales of Gods, Goddesses, and Heroes by Philip Freeman (narrated by Gerard Doyle). Use my link to get 3 free months of Audible Premium Plus and you can listen to the full 7.5-hour audiobook for free.