I thoughht I'd posted this last night - from UFO site!
"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.
