This hillfort is clearly seen from, and incidentally dominates, the excellent hillfort and broch of Edin's Hall to the NE. Clearly this raises issues regarding period(s) of occupation... no authority with the power base sufficient to erect such a substantial broch would have tolerated anything other than a totally compliant community upon Cockburn Law... and what would have been the point of that anyway, bearing in mind the size of Edin's Hall? I guess the assumption must be that Cockburn Law was an earlier settlement superseded by the lower placed enclosure, perhaps being used merely as an advanced 'look out' point, if not totally abandoned? Then again, since the ramparts surround what may have been a Bronze Age cairn, was its function purely symbollic. Surely not? Well, check out the surrounding water courses which leave only a relatively narrow approach to approx SW... coincidence, excellent defensive siting...or something more?
Anyway, according to Canmore:-
"...The side of easiest approach is defended by three earth and stone ramparts (there is no evidence of ditches) with two staggered entrances. On the E side a single low rampart follows the top of steep natural hillslopes. A wide linear boulder spread which runs parallel to the foot of these slopes may be a further line of defence. A third entrance (on the S side of the fort) is approached by a terraced way. The 0.2m high stony banks which form the curvilinear internal detail at the summit cannot be readily interpreted; the two level circular areas may be the sites of huts, but the alleged cairn is not clearly identifiable".