Many stones are sintered, but how that happened remains a mystery. The high temperature which is needed for sintering can only be achieved by means of a special oven, not in open air.
Evidence of the very real possibility of such events in our distant past can be seen in the existence of a large number of enigmatic, highly vitrified ruins that can be found in many parts of the world. The scattered nature of these ruins, including areas of Scotland, France, Turkey and the Middle East and the vitrified stones they contain is something that just cannot be easily explained. According to author David Hatcher-Childress, there are at least 60 such vitrified forts that exist just throughout Scotland alone! Among the most well-known of these Scottish ruins are Tap o'Noth, Dunnideer, Craig Phadraig (near Inverness), Abernathy (near Perth), Dun Lagaidh (in Ross), Cromarty, Arka-Unskel, Eilean na Goar, Bute-Dunagoil on the Sound of Bute off Arran Island and the Cauadale hill-fort in Argyll, West Scotland.
Perhaps the best example of them is said to be Tap o'Noth, which is near the village of Rhynie in North-eastern Scotland. The ruins are of a massive fort was built high on the summit of the Tap o'Noth mountain at a height of 1,859 feet. At first glance it appears that the walls of the fortress are made of a blackened, cindery rubble, but on a closer examination becomes strikingly evident that they are actually made of melted and fused together rocks!
What were once individual stone blocks within the walls are now black, and glassy masses that have been fused together by a heat that was in places, so intense that the remains of actual molten rivulets of rock that once ran down the walls like melting wax can still be seen quite clearly.
One early theory proposed was that the forts are located on the remains of ancient volcanoes and that the people used molten stone being ejected from the eruptions to build their settlements. I’m not sure whose brainwave the idea actually was, but it seems somewhat fanciful at best.
That theory however, was soon replaced with the notion that the vitrification was in fact, done on purpose, in order to strengthen the walls. This theory purported that the builders had perhaps designed the forts in that fashion, surmising that fires had been lit so as to temper the stone in order to produce walls strong enough to resist both the invading armies and possibly the dampness of the local climate. It’s an interesting theory to say the least, but one that has a number of serious problems. Firstly, there is no indication that such vitrification does actually strengthen the walls in any way at all and secondly, there is every indication that the fire in fact weakens them substantially. In many cases, the walls of the fortresses seem to have almost totally collapsed because of the fires. Also, since the walls of many Scottish forts are only partially vitrified, it does not seem to have been done purposely as walls that have only been partially completed would hardly have been considered to have been an effective fortification.
It must be appreciated that some of these ruins are massive too, indicating that they were once occupied by extremely large forces. In one section of the book ‘Mysterious Britain’ the authors Janet and Collin Bord discuss the vastness of the ruins of ‘Maiden Castle’ in Scotland which gives a good indication of the enormous size of some of these ancient fortresses:
“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 11.2 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.” Numerous vitrified remains can also be found in the western United States. One such site was discovered in Death Valley by the American explorer Captain Ives William Walker in 1850. Walker apparently discovered a city about a mile long with the lines of the streets and the positions of the buildings still visible. At the centre of the site was a huge rock, between 20 to 30 feet high, with the remains of an enormous structure atop it. The southern side of both the rock and the building was melted and vitrified. Walker assumed that a volcano had been responsible for this phenomenon, but there is no volcano in the area. In addition, tectonic heat could not possibly have caused such visible liquification on the surface of the rock.
More vitrified ruins can also be found in France, Turkey, India and some areas of the Middle East. Some of the ancient ziggurats of Iran and Iraq also contain vitrified material. Some of the vitrification on these ruins is thought by some archaeologists to have been caused by the very ancient and very mysterious Greek fire.
The vitrified remains of the ziggurat at Birs Nimrod (Borsippa), south of Hillah that were once thought to be the Tower of Babel, are also crowned by a large mass of vitrified stone brickwork and actual baked clay bricks that have all been fused together by some type of truly intense heat.