A degree of resolve is required to visit Dun Kearstack, a galleried, Iron-Age dun which lies half a kilometre or so up Glen Boreraig. There is no possibility of accessing this glen other than on foot, and the best starting point is from the end of the metalled road that leads from Kilbride (near Torrin) to the shore of Loch Slapin at Camas Malag (where there is space to park).
The first stretch follows the excellent coastal path south for just over 2¼ kilometres, until you reach the bridge over the 2nd of the two streams issuing from Glen Boreraig: then (without crossing the bridge) you must pick your way east up the glen across almost trackless moorland to the dun. The former fort cannot be seen from below, and a degree of trial and error may be needed to locate it. Suffice it to say that, once you have gained the necessary altitude, it is readily apparent where it lies.
The GoogleMap below shows Glen Boreraig, with the two streams fairly evident. The dun lies between these streams. The bridge in question lies at the point where the path dips farthest east (to the right).
The fort, which sits atop a huge mound, is very dilapidated, most of the walling having collapsed down the slopes. But it does afford great views down Glen Boreraig to both Blaven and Clach Glas on the far shore of Loch Slapin, and to the Cuillin beyond.