Another form of archaeological remains found in the county is the Eirde or Earth-Houses. These are subterranean dwellings dug out of the ground and walled with unhewn, unmortared stones, each stone overlapping the one below until they meet at the top which is crowned with a larger flag-stone, or sometimes with wood. The probability is that in conjunction with the underground chambers there were huts above ground, which, being composed of wood, have now entirely disappeared. At many points in these earth-houses traces of fire and charcoal are to be seen, stones blackened by fire and layers of black ashes. In one at Loch Kinnord a piece of the upper stone of a quern as well as an angular piece of iron was found. It may be inferred that the inhabitants, whoever they were, were agriculturists, and that the period of occupation lasted down to the Iron Age. Specimens of these houses, which usually go by the local name of Picts’ houses, are found in the neighbourhood of Loch Kinnord on Deeside, at Castle Newe on the Don, and at Parkhouse, not far from the circle already referred to. [Illustration: “PICTS” OR “EIRDE HOUSE” AT MIGVIE ABERDEENSHIRE From _Proceedings of the Society of Antiquaries of Scotland_, Vol. V. 1865] The common notion of the purpose of these underground dwellings was that they were meant for hiding-places in which the inhabitants took refuge when unable to resist their enemies in the open, but if, as has now been discovered, they were associated with wooden erections above ground, they could not have served this purpose. On the surface beside them were other houses, cattlefolds and other enclosures; once an enemy was in possession of these, he could hardly miss the earth-houses. Moreover, the inhabitants, if discovered, were in a trap from which there was no escape. It is more probable that the dwellings were adjuncts of some unknown kind to the huts on the surface. The fact that pottery and bronze armlets have been unearthed from these underground caverns proves that the earth-dwellers had reached a certain advancement in civilisation. They reared domestic animals, wove cloth and sewed it, and manufactured pottery. They used iron for cutting weapons and bronze for ornament, and must have possessed a wonderfully high standard of taste and manual skill. Along with the earth-houses at Kinnord are found crannogs or lake-dwellings. Artificial islands were created in the loch by forming a raft of logs, upon which layers of stones and other logs were deposited. As fresh materials were added the raft gradually sank till it rested on the bottom. The sides were afterwards strengthened with the addition of stones and beams. In this way was formed what is called the Prison Island on Loch Kinnord. In all probability the other island in the same loch, the Castle Island, may also be artificial, although it has usually been regarded as natural. Crannogs in pairs—one large and the other small—occur in several lochs.