CAVAN, Ireland – From the Irish county of Cavan have come reports of serious but unspecified damage to a 3000 year old hill fort.
Archaeologist Michael Gibbons first noticed the damage, when visiting the area with Galway’s heritage officer Dr Jim Higgins, and it was confirmed by aerial photography. He lodged a notification with the Department of Public Works and the Department of Culture, Heritage and the Gaeltacht have launched an enquiry with the National Monuments Service, which is still in progress.
Unfortunately, however, the fort – although a listed monument – is on private land, and the Department says that it is, “not a national monument in the ownership of the state and the Office of Public Works does not, therefore, have a role with regard to its care and protection.”
Mr Gibbons has deplored this state of affairs and says that the fort ought to have been taken under public protection. He told radio station Northern Sound that investment in these sites is greatly underfunded in Ireland as compared to Scotland, and that the Irish Department of Agriculture, which does have a large budget, needs to put more work into educating farmers with regard to the importance of these ancient sites.
Not only is the Shantemon fort unusual for Ireland, but Gibbons believes it to be an example of the connections between the northeast of the country and Scotland.
Gibbons says that the hill fort in question is the only one of its kind in Ireland: it is a so-called “vitrified fort,” which means that, as the name suggests, it was made of stone (without mortar) but was then probably covered with timber and set alight, the 700-1000 degree Celsius heat altering the appearance of the stone.
It’s not clear whether this was done deliberately initially, or whether it was a result of warfare: it apparently does not make the walls of a fort easier to scale, or destroy them, or make them more fragile. So is unknown whether the process was destructive or constructive.
This process has previously appeared a little mysterious: SF writer Arthur C Clarke claimed that vitrified forts were the biggest mystery he had encountered and even suggested that Stone Age people would need to possess lasers to achieve these results.
There have been attempts to reproduce the effect in the 20th century – for example, by archaeologists Thorneycroft and Child in the 1930s – but with limited success. Some commentators have suggested that the heat required to fuse stone is so high that the phenomenon could only be explained by a prehistoric atomic blast!
However, intriguing that suggestion, and that it was made by Sir Arthur, might be, other researchers have pointed out that such buildings were constructed in the middle of the Iron Age, in which metalworking, forging and vitrification were hardly new: people have been estimated to have been melting ore for 10,000 years before this period. Additionally, atomic weaponry leaves particular signatures which have not been in evidence in the case of the vitrified forts.
Researcher Brian Dunning states,
Keep in mind also that Thorneycroft and Childe were archaeologists with minimal stone melting skills, while the men who vitrified the forts two and a half millennia before them were expert professionals whose knowledge was based on centuries of experience.
It’s important to keep in mind that wherever an Iron Age fortification was under construction, the supporting infrastructure of workers and local people would certainly have included blacksmiths, whose furnaces of the day reached some 1300°C. There was no lack for expertise in the arts of building smelting fires or keeping them hot.
Dunning goes on to say,
We’ve learned that the technology required to create the vitrified forts was not extraordinary. Nothing found at the sites requires any re-examination of the history of knowledge. The questions that do remain are sociological. Why were the forts vitrified, and who vitrified them? I’m happy to report that we don’t know yet, and that this is one more item to add to our list of mysteries still to be solved.
Dunning’s cautious approach has been supported by more recent studies of Dun Deardail fort near Ben Nevis in Scotland, in which a 2018 report of experiments has shown that vitrification of stone can be produced by a very high heat from above: the stone fuses in anerobic conditions.
However, Matt Ritchie, archaeologist with Forestry Enterprise Scotland, adds that although the question of the forts’ actual technical construction has now been solved,
“…the mystery of why the forts were burned remains unsolved. Was it accidental, or intended? Was it an act of destruction, by a victorious foe, or an act of ceremony, perhaps on the death of a revered king? We may never know.”
There are about 70 such forts throughout the British Isles, in Scotland, and more across the European continent. However, the subject of this article, in Shantemon near Cavan, is, as we’ve noted, Ireland’s sole example. It dates from 1200 – 1000 B.C and was first identified as a “vitrified” fort by clergyman and author the Reverend Caesar Otway, who wrote up his find in the Transactions of the Royal Irish Academy in 1818.
The fort is marked on an early Ordnance Survey map of the area, which has other monuments, including a stone row known as “Fionn MacCumhaill’s Fingers.”
Shantemon Hill is also believed to have been the inauguration site of the O Raghallaigh (O’Reilly) family from 12th to the 17th century. An inauguration stone known as ‘Cois an tSiorragh’ (‘the foal’s foot’) was found here, resembling a little hoof, and it has been suggested that this was where inaugurations took place although the current location of this stone is now unknown.
Folklore claims that Fionn MacCumhaill lost a hand in battle here – the fallen boulder is his thumb – but as writer Ed Hannon points out, as with most relics, Fionn would need to have had about ten hands given the heritage sites associated with him!
In relation to the fort itself, it is to be hoped the investigation gets to the bottom of the damage caused to this unique monument.