Archaeologists have suggested ways to organise the very varied “vitrified forts” into formal classes – especially schemes that distinguish forts Read more
One of the great mysteries of classical archaeology is the spartan worldwide distribution of vitrified forts, except for Scotland and France. However, there are a number in the wider world, especially Europe. Here is the current breakdown:
Global (really pan-European) picture of vitrified hill-forts
To date, all firmly identified vitrified forts lie in western and Northern Europe. More than 200 sites are accepted; c. 70 of them are in Scotland—the densest cluster anywhere. No authenticated examples are recorded in the Near East, Africa, the Americas or Australasia.
Isolated, limited vitrification reported at Pen Dinas (Ceredigion) and South Barrule (Man), but not as extensive as the Scottish walls.
Requires modern material’s analysis; both often cited but thinly published.
Ireland
Fewer than ten candidate sites; best-known are Dun Aengus (Aran Is.), Knocknashee (Sligo) and possibly Creggankeel. Vitrification tends to be patchy.
Field confirmation lagging; dating work only recently begun.
France
c. 20 forts, concentrated in Brittany (e.g., Le Yaudet), Normandy and Burgundy (e.g., Château de la Roche). Roland Comte, however, has suggested that there may be many more.
French excavations since the 1980s apply high-temperature petrology; some walls show repeat vitrification events.
Atlantic/North-Sea façade cluster: Scotland, Brittany and southern Sweden share the densest concentrations, suggesting cultural transmission along maritime routes during the mid-first-millennium BC.
Sparse but widespread inland occurrences: Single forts in Germany, Bohemia and the upper Danube imply that vitrification was known but never commonplace on the mainland.
Absence outside Europe: Claims of vitrified “desert forts” or Asian walls have not survived petrological scrutiny; temperatures reached in those structures derive from natural lightning or later lime-kiln intrusions, not deliberate timber-lacing fires.
Research gaps
Analytical parity: Scotland, France and Sweden have applied SEM, XRD and Lead-isotope analysis; many Iberian, Irish and Central-European sites still rely on macroscopic description.
Chronological resolution: Fewer than 25 forts have direct radiocarbon or OSL dates for the firing episode; comparative regional chronologies therefore remain coarse.
Functional explanation: Whether vitrification was accidental, tactical, or ritual continues to be debated across the entire distribution area; consistent excavation strategies are needed if we are to compare motives between the Scottish core and outlier regions.
In sum, vitrified forts form a European phenomenon centred on Scotland but echoed in discontinuous belts from Iberia to Scandinavia, with isolated outliers deep in Central Europe. Their patchy yet recognisable distribution hints at shared construction methods—and perhaps shared symbolic practices—diffusing across Iron-Age Europe, never extending beyond it. (Nature, ResearchGate, Amusing Planet)
There are at least 70 such forts throughout Scotland. Among the most well-known are Dunnideer, Craig Phadraig (near Inverness), Abernathy (near Perth), Dun Lagaidh (in Ross), Cromarty, Arka-Unskel, Eilean na Goar, and Bute-Dunagoil on the Sound of Bute off Arran Island. Another well-known vitrified fort is the Cauadale hill-fort in Argyll, West Scotland.
Others include, Dun Mac Uisneachain (Dun Macsnoichan), the ancient Beregoiium, about 9 m. N.N.E. of Oban; Tap o’ Noth, in Aberdeenshire; Craig Phadraic, or Phadrick, near Inverness; Dun Dhardhail (Dunjardil) in Glen Nevis; Knockfarrail, near Strathpeffer; Dun Creich, in Sutherland; Finhaven, near Aberlemno; Barryhill, in Perthshire; Laws, near Dundee; Dun Gall and Burnt Island, in Buteshire; Anwoth, in Kirkcudbright; and Cowdenknowes, in Berwickshire. Dun Mac Tjisneachain is the largest in area, being 250 yds. long by 50 yds. broad. In Barryhill and Laws, the remains of small rectangular dwellings have been found.
The evidence from elsewhere shows very few vitrified forts elsewhere, indeed the total number of vitrified forts worldwide is thought to be less than 100. Some examples are as follows:
France
Vitrified forts in France are discussed in the American Journal of Science (vol. 3, no. 22, 1881, pp. 150-151) in an article entitled “On the Substances Obtained from Some ‘Forts Vitrifiés’ in France”, by M. Daubrée. The author mentions several forts in Brittany and northern France whose granite blocks have been vitrified. He cites the “partially fused granitic rocks from the forts of Château-vieux and of Puy de Gaudy (Creuse), also from the neighbourhood of Saint Brieuc (Côtes-du-Nord)”. Daubrée, understandably, could not readily find an explanation for the vitrification.
Vitrified stones, hillfort in Highland, Scotland, UK, Rubh’ Ard Ghaunsgail
Very vitrified. Possibly part of the pictish fort that was here.
Turkey
Similarly, the ruins of Hattusas in central Turkey, an ancient Hittite city, are partially vitrified. The Hittites are said to be the inventors of the chariot, and horses were of great importance to them. It is on the ancient Hittite stelae that we first see a depiction of the chariot in use. However, it seems unlikely that horsemanship and wheeled chariots were invented by the Hittites; it is highly likely that chariots were in use in ancient China at the same time.
Iran
Some of the ancient ziggurats of Iran and Iraq also contain vitrified material, sometimes thought by archaeologists to be caused by the Greek fire. For instance, the vitrified remains of the ziggurat at Birs Nimrod (Borsippa), south of Hillah, were once confused with the Tower of Babel. The ruins are crowned by a mass of vitrified brickwork–actual clay bricks fused together by intense heat. This may be due to the horrific ancient wars described in the Ramayana and Mahabharata, although early archaeologists attributed the effect to lightning.
Other locations
Vitrified forts have also been found in Yorkshire and Lancashire, in England; Londonderry and Cavan, in Ireland; in Upper Lusatia, Bohemia, Silesia, Saxony and Thuringia; in the provinces on the Rhine, especially in the neighbourhood of the Nahe; in the Ucker Lake, in Brandenburg, where the walls are formed of burnt and smelted bricks; in Hungary.
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