The Vitrified Forts of Scotland:

How do you vitrify a fort?

There have been many theories as to how vitrification has occured in some ancient forts, ranging from the use of special chemicals to the composition of the rocks used for the forts. As a result of our research we have concluded that the in order to create a "true" vitrified rampart, the heat required is in excess of that that which would normally be the case if the rampart alone was the only fuel. Temperatures in excess of 1000 degrees Centigrate would need to be applied consistently over large areas of the wall, in close proximity for a significant period of time.

To build hot fires, one has to remember two things, it is the combination of the fuel and oxygen that is creating the fire, the best fuels present the maximum surface area to the air. We can understand the difficulty of reaching consistently high temperatures what we consider the effort required to turn iron molton - 1050 degrees, here belows need to pump gusts of "wind" into a kiln, which is constructed to reflect the heat back into the furnace, the hottest kilns, use coal or coke, their granular composition combined with the forced air flow serve to maximise the air to fuel ratio. Clearly, the concept of a wall constructed with heavy timber beams, separated by layers of rock, reaching such extreme temperatures is difficult to imagine. It has been suggested that the correct wind conditions may serve to "fan" a fire, perhaps after the rampart had been set on fire during an attack, but it must be remember that for a furnace to reach these sorts of temperatures the fire is enclosed and the heat relected in, an open fire stands little chance of reaching such temperatures without much greater amounts of fuel.

Given this, it is clear that vitrified ramparts are the result of a deliberate and continued effort.information, it has been suggested that some forts used imported stonevitrified forts involved a specially constructed rampart, its stone is not easily vitrified would be covered with more suitable rock which would melt onto the base rock in a similar way that enamel melts into clay to form pottery. Additional chemicals such as sea salt may have also been used to increase the temperature of the process and to act as a 'flux' to help the rock join. Wood was used as the main fuel, perhaps Oak or Yew which were widely available and have a high natural burning temperature.

However, these two factors of there own will not produce vitrification to a satisfactory level. In order to consistently achieve a satisfactory level of vitrification the heat produced by the fire must be concentrated and directed towards the ramparts. It is therefore suggested that during their construction/modification the rampart will have been shrouded by a wood and turf structure, which turned the rampart into the interior of a kiln. To date no evidence of such a structure exists but the limited excavations performed on vitrified sites and the nature of vitrification mean that this is not surprising. In all, the following factors have lead to our conclusion:

(1) Many of the Primary rocks, particularly the schists, gneisses and traps, which contain large quantities of potash and soda, can be readily fused in the open air by means of wood fires—the alkali of the wood serving in some measure as a flux. (2) The walls are chiefly vitrified at the weakest points, the naturally inaccessible parts being unvitrified. (3) When the forts have been placed on materials practically infusible, as on the quartzose conglomerates of the Old Red Sandstone, as at Craig Phadraic, and on the limestones of Dun Mac Uisneachain, pieces of fusible rocks have been selected and carried to the top from a considerable distance. (4) The vitrified walls of the Scottish forts are invariably formed of small stones which could be easily acted upon by fire,whereas the outer ramparts where used, are not vitrified and are built of large blocks. (5) Many of the continental forts are so constructed that the fire must have been applied internally, and at the time when the structure was being erected. (6) Daubrée, in an analysis which he made on vitrified materials taken from four French forts, and which he submitted to the Academy of Paris’ in February 1881, found the presence of natron in such great abundance that he inferred that sea-salt was used to facilitate fusion.

One of the great mysteries of classical archaeology is the existence of many vitrified forts in Scotland. Are they also evidence of some ancient atomic war? Maybe, but maybe not. 

There are said to be at least 60 such forts throughout Scotland. Among the most well-known are Tap o'Noth, 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.

One of the best examples of a vitrified fort is Tap o'Noth, which is near the village of Rhynie in northeastern Scotland. This massive fort from prehistory is on the summit of a mountain of the same name which, being 1,859 feet (560 metres) high, commands an impressive view of the Aberdeenshire countryside. At first glance it seems that the walls are made of a rubble of stones, but on closer look it is apparent that they are made not of dry stones but of melted rocks! What were once individual stones are now black and cindery masses, fused together by heat that must have been so intense that molten rivers of rock once ran down the walls. 

Reports on vitrified forts were made as far back as 1880 when Edward Hamilton wrote an article entitled "Vitrified Forts on the West Coast of Scotland" in the Archaeological Journal (no. 37, 1880, pp. 227&endash;243). In his article, Hamilton describes several sites in detail, including Arka-Unskel:4

At the point where Loch na Nuagh begins to narrow, where the opposite shore is about one-and-a-half to two miles distant, is a small promontory connected with the mainland by a narrow strip of sand and grass, which evidently at one time was submerged by the rising tide. On the flat summit of this promontory are the ruins of a vitrified fort, the proper name for which is Arka-Unskel.

The rocks on which this fort are placed are metamorphic gneiss, covered with grass and ferns, and rise on three sides almost perpendicular for about 110 feet from the sea level. The smooth surface on the top is divided by a slight depression into two portions. On the largest, with precipitous sides to the sea, the chief portion of the fort is situated, and occupies the whole of the flat surface. It is of somewhat oval form. The circumference is about 200 feet, and the vitrified walls can be traced in its entire lengthÉ We dug under the vitrified mass, and there found what was extremely interesting, as throwing some light on the manner in which the fire was applied for the purpose of vitrification. The internal part of the upper or vitrified wall for about a foot or a foot-and-a-half was untouched by the fire, except that some of the flat stones were slightly agglutinated together, and that the stones, all feldspatic, were placed in layers one upon another.

It was evident, therefore, that a rude foundation of boulder stones was first formed upon the original rock, and then a thick layer of loose, mostly flat stones of feldspatic sand, and of a different kind from those found in the immediate neighborhood, were placed on this foundation, and then vitrified by heat applied externally. This foundation of loose stones is found also in the vitrified fort of Dun Mac Snuichan, on Loch Etive.

Hamilton describes another vitrified fort that is much larger, situated on the island at the entrance of Loch Ailort. 

This island, locally termed Eilean na Goar, is the most eastern and is bounded on all sides by precipitous gneiss rocks; it is the abode and nesting place of numerous sea birds. The flat surface on the top is 120 feet from the sea level, and the remains of the vitrified fort are situated on this, oblong in form, with a continuous rampart of vitrified wall five feet thick, attached at the SW end to a large upright rock of gneiss. The space enclosed by this wall is 420 feet in circumference and 70 feet in width. The rampart is continuous and about five feet in thickness. At the eastern end is a great mass of wall in situ, vitrified on both sides. In the centre of the enclosed space is a deep depression in which are masses of the vitrified wall strewed about, evidently detached from their original site.

Hamilton naturally asks a few obvious questions about the forts. Were these structures built as a means of defence? Was the vitrification the result of design or accident? How was the vitrification produced?

In this vitrification process, huge blocks of stones have been fused with smaller rubble to form a hard, glassy mass. Explanations for the vitrification are few and far between, and none of them is universally accepted. 

One early theory was that these forts are located on ancient volcanoes (or the remains of them) and that the people used molten stone ejected from eruptions to build their settlements.

This idea was replaced with the theory that the builders of the walls had designed the forts in such a way that the vitrification was purposeful in order to strengthen the walls. This theory postulated that fires had been lit and flammable material added to produce walls strong enough to resist the dampness of the local climate or the invading armies of the enemy. It is an interesting theory, but one that presents several problems. For starters, there is really no indication that such vitrification actually strengthens the walls of the fortress; rather, it seems to weaken them. In many cases, the walls of the forts seem to have collapsed because of the fires. Also, since the walls of many Scottish forts are only partially vitrified, this would hardly have proved an effective building method.

Julius Caesar described a type of wood and stone fortress, known as a murus gallicus, in his account of the Gallic Wars. This was interesting to those seeking solutions to the vitrified fort mystery because these forts were made of a stone wall filled with rubble, with wooden logs inside for stability. It seemed logical to suggest that perhaps the burning of such a wood-filled wall might create the phenomenon of vitrification.

Some researchers are sure that the builders of the forts caused the vitrification. Arthur C. Clarke quotes one team of chemists from the Natural History Museum in London who were studying the many forts:5 

Considering the high temperatures which have to be produced, and the fact that possibly sixty or so vitrified forts are to be seen in a limited geographical area of Scotland, we do not believe that this type of structure is the result of accidental fires. Careful planning and construction were needed.

However, one Scottish archaeologist, Helen Nisbet, believes that the vitrification was not done on purpose by the builders of the forts. In a thorough analysis of rock types used, she reveals that most of the forts were built of stone easily available at the chosen site and not chosen for their property of vitrification.6

The vitrification process itself, even if purposely set, is quite a mystery. A team of chemists on Arthur C. Clarke's Mysterious World subjected rock samples from 11 forts to rigorous chemical analysis, and stated that the temperatures needed to produce the vitrification were so intense--up to 1,100°C--that a simple burning of walls with wood interlaced with stone could not have achieved such temperatures.7

Nevertheless, experiments carried out in the 1930s by the famous archaeologist V. Gordon Childe and his colleague Wallace Thorneycroft showed that forts could be set on fire and generate enough heat to vitrify the stone.8 In 1934, these two designed a test wall that was 12 feet long, six feet wide and six feet high, which was built for them at Plean Colliery in Stirlingshire. They used old fireclay bricks for the faces and pit props as timber, and filled the cavity between the walls with small cubes of basalt rubble. They covered the top with turf and then piled about four tons of scrap timber and brushwood against the walls and set fire to them. Because of a snowstorm in progress, a strong wind fanned the blazing mixture of wood and stone so that the inner core did attain some vitrification of the rock.

In June 1937, Childe and Thorneycroft duplicated their test vitrification at the ancient fort of Rahoy, in Argyllshire, using rocks found at the site. Their experiments did not resolve any of the questions surrounding vitrified forts, however, because they had only proven that it was theoretically possible to pile enough wood and brush on top of a mixture of wood and stone to vitrify the mass of stone. One criticism of Childe is that he seems to have used a larger proportion of wood to stone than many historians believe made up the ancient wood and stone fortresses.

An important part of Childe's theory was that it was invaders, not the builders, who were assaulting the forts and then setting fire to the walls with piles of brush and wood; however, it is hard to understand why people would have repeatedly built defences that invaders could destroy with fire, when great ramparts of solid stone would have survived unscathed.

Critics of the assault theory point out that in order to generate enough heat by a natural fire, the walls would have to have been specially constructed to create the heat necessary. It seems unreasonable to suggest the builders would specifically create forts to be burned or that such a great effort would be made by invaders to create the kind of fire it would take to vitrify the walls--at least with traditional techniques.

One problem with all the many theories is their assumption of a primitive state of culture associated with ancient Scotland. 

It is astonishing to think of how large and well coordinated the population or army must have been that built and inhabited these ancient structures. Janet and Colin Bord in their book, Mysterious Britain,9 speak of Maiden Castle to give an idea of the vast extent of this marvel of prehistoric engineering. 

It covers an area of 120 acres, with an average width of 1,500 feet and length of 3,000 feet. The inner circumference is about 11Ú2 miles round, and it has been estimated...that it would require 250,000 men to defend it! It is hard, therefore, to believe that this construction was intended to be a defensive position.

A great puzzle to archaeologists has always been the multiple and labyrinthine east and west entrances at each end of the enclosure. Originally they may have been built as a way for processional entry by people of the Neolithic era. Later, when warriors of the Iron Age were using the site as a fortress, they probably found them useful as a means of confusing the attacking force trying to gain entry. The fact that so many of these "hill-forts" have two entrances--one north of east and the other south of west--also suggests some form of Sun ceremonial.

With 250,000 men defending a fort, we are talking about a huge army in a very organised society. This is not a bunch of fur-wearing Picts with spears defending a fort from marauding bands of hunter-gatherers. The questions remain, though. What huge army might have occupied these cliffside forts by the sea or lake entrances? And what massive maritime power were these people unsuccessfully defending themselves against?

The forts on the western coast of Scotland are reminiscent of the mysterious clifftop forts in the Aran Islands on the west coast of Ireland. Here we truly have shades of the Atlantis story, with a powerful naval fleet attacking and conquering its neighbours in a terrible war. It has been theorised that the terrible battles of the Atlantis story took place in Wales, Scotland, Ireland and England--however, in the case of the Scottish vitrified forts it looks as if these were the losers of a war, not the victors. And defeat can be seen across the land: the war dykes in Sussex, the vitrified forts of Scotland, the utter collapse and disappearance of the civilisation that built these things. What long-ago Armageddon destroyed ancient Scotland?

In ancient times there was a substance known through writings as Greek fire. This was some sort of ancient napalm bomb that was hurled by catapult and could not be put out. Some forms of Greek fire were even said to burn under water and were therefore used in naval battles. (The actual composition of Greek fire is unknown, but it must have contained chemicals such as phosphorus, pitch, sulphur or other flammable chemicals.)

Could a form of Greek fire have been responsible for the vitrification? While ancient astronaut theorists may believe that extraterrestrials with their atomic weapons vitrified these walls, it seems more likely that they are the result of a man-made apocalypse of a chemical nature. With siege machines, battleships and Greek fire, did a vast flotilla storm the huge forts and eventually burn them down in a hellish blaze?

The evidence of the vitrified forts is clear: some hugely successful and organised civilisation was living in Scotland, England and Wales in prehistoric times, circa 1000 BC or more, and was building gigantic structures including forts. This apparently was a maritime civilisation that prepared itself for naval warfare as well as other forms of attack. www.

Scotland

There are at least 50 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 worldwidde 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.

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