Some of the finest of this class of prehistoric remains which we have seen in Ireland occur near the shore of Lough Gur, a spot noted for the number and variety of its antiquities, one hundred of which are known to have existed within the memory of man. Lough Gur lies about ten miles south of Limerick on the road to Bruff; and the first account of its antiquities was given by Crofton Croker in 1830, after three days’ investigation, extending over a tract of country fifteen miles in length. ‘The finest circle is 56 yards in diameter, and consists of a very large number of upright blocks closely arranged and flanked by a great bank of earth. It is approached by a passage 12 feet long, the entrance being guarded by two blocks, close to which is one 8 feet by 7 feet, and over 3 feet thick. In a field to the north-west are traces of two more circles, one with a centre stone; and in the next field to the north, the remains of another, 65 yards in diameter, of smaller stones than the first.’ On the verge of the lake further east is a small circle of seven fallen stones; to the north of Knockadun Hill are three complete circles, two being concentric.[55] [Illustration: Stone Circle at Slieve na Greidle, Co. Down.] For our purpose, however, a sufficient number of typical examples have already been given. * * * * * _Alignments._--At Carnac in Brittany, at Ashdown, Berkshire, in Caithness, and in Sutherland may be seen lines of stone placed upon end, and generally some few feet apart. The row is occasionally of a length not exceeding a few yards; but sometimes it appears to cover a great extent of ground. The stones vary in size, some of the blocks being of large proportions, and others measuring barely 3 or 4 feet in height. All are invariably unhewn, presenting the appearance of rough surface stones, or of such as are usually found in glacial-scooped ravines or river-beds. These lines are usually in parallel rows, varying in number to ten or more. For want of a better name they have been variously styled avenues, alignments, rows, parallelitha. From the days of Stukeley they have been the subject of much speculation, and we have little beyond conjecture in regard to their uses. They seem like ‘galleries which lead to nothing’; yet their construction affords unmistakable evidence of organized labour and deliberate design.