vallum, the remains of two of which exist.[84] About half a mile to the west of Dunbeg is _Cahernamactirech_, the ‘Fort of the wolves.’[85] The walls vary from 11 to 18 feet in thickness, enclosing an area of about 100 feet in diameter. Three sections of the wall, occupying the greater portion of it, were pierced by narrow passages, and a number of clochauns occupied the area within. This was a most interesting fortification, and had some unusual features; but it has fallen into great dilapidation. Du Noyer was of opinion that the Fahan settlement dated from the Firbolg occupation. O’Curry combated this in supporting the theory that it was of primitive Christian origin and a monastic establishment.[86] Mr. Stewart Macalister is of opinion that ‘the clochan period of the settlement probably extends from a little before the introduction of Christianity into Corkaguiney, down to a comparatively recent date in the Middle Ages.’[87] [Illustration: Dunamoe Fort, Co. Mayo.] At Dunamoe Point, on the north-west coast of the Mullet peninsula, are the remains of a fine cashel, which crosses the neck of the headland. The wall is 210 feet long, 8 feet thick, and 18 feet high in places; but it is in a state of dilapidation. Without is a fosse and a slight abatis. Within the wall are the remains of three clochauns, and a ruined circular fort, about 100 feet in diameter. [Illustration: The ‘School House’ (Bee-hive hut), Inismurray.] [Illustration: Section of an ordinary underground beehive-shaped hut.]