_Caher or Cashel._--Where stone was abundant, as in Kerry, Clare, the Arran Islands, Mayo, Sligo, and other districts, the defences consisted of walls of dry masonry called _Cathairs_ (Cahers), or _Caiseals_ (Cashels). Many of these are found on projecting headlands, or on steep precipitous cliffs, the line of defence crossing and enclosing a portion of land that had a natural protection seawards. Cashels existed too in exposed situations on hill-tops and bleak uplands. The walls usually show that two faces were built many feet apart with a batter, and the interior filled up with a mass of rough rubble which, in settling, often brought destruction on the walls. Others, however, were constructed of two or more walls lying close together and apparently forming one mass, reaching a thickness of 16 to 18 feet. The inner wall was formed into flights of steps leading to a platform lower than the outside wall, and on which a stand could be taken for defence. The gateways are of particular interest and of varied features; the more general kind have inclined sides, a heavy lintel, and a regular course of masonry through the wall. Passages and chambers exist within some of these cashels, intended, no doubt, like the souterrains, as places of retreat in time of danger. These stone forts were sometimes defended by outer works, as in the case of Dunbeg (Kerry) and Moghane (Clare), or by a _chevaux-de-frise_ of sharp stones set in the ground, as at Dun Ængus and Dubh Caher in Aranmore, Ballykinvarga in Clare, and Dunamoe in Mayo. Many of the cashels contain small stone-roofed buildings called _Clochauns_, or bee-hive huts. These are circular or oval in plan, and the walls converge upwards by the gradual approximation of the horizontal layers of stones until the top is reached and closed by a single slab, as in the case of the chambers in the tumuli. Examples of these singular structures are to be found in Kerry, Aranmore, Inismurray, and elsewhere. They are of especial interest, not only as dating from pre-Christian times, but because they were adopted by the early missionaries, with such modifications as necessity required, as models of the monastic cells and oratories. The circular bee-hive hut was necessarily of very moderate dimensions; but the difficulty of space was sometimes overcome by connecting two or three together by short passages, as in the clochauns in the neighbourhood of Dingle. The bee-hive cells in this district are among the most remarkable now remaining; some of them contain souterrains with a trap-like entrance from the floor. * * * * * [Illustration: Staigue Fort, Co. Kerry.]