Parked at L851 751 A (good space for 2 cars) and first climbed to L851 740 B (the unnamed peak 388m, SW of Knockakishaun) to make the day longer! Some rough ground up and down on this one. So, on to Knockakishaun (390m). After crossing the Bunowen river at L863 743 C we headed N. atop the steep ridge and on to the spot hight 390 on generally very good ground. Some great glacial errata along the way before the 300m contour. Well worth the effort, the snow topped Sheefrys, Mweelrea and C. Patrick in close proximity giving an alpine foothills feeling! Linkback: https://mountainviews.ie/summit/853/comment/6276/

Parked at a layby further up the valley from the crossing point mentioned in James Sheerin's comment to do a circuit of Laghta Eighter and Knockakishaun. Access to Laghta Eighter was easy from higher up the valley, no enclosures, fences, etc. Coming back to the road between Laghta Eighter and Knockakishaun, I spoke to a passing farmer from the valley who said I was welcome to head up Knockakishaun from here, through the enclosed fields, but that crossing the Bunowen river might be easier higher up. I walked upriver a bit, but after the fairly rainy weather recently, the river was up and there seemed to be no comfortable crossing place anywhere.

So I drove back down the valley back past L852 751 D where the road crosses the river and parked at a layby opposite a house a bit further down at around L848 755 E. From here a short traverse across bog quickly gives way to a fairly straightforward walk up the boulder-strewn slopes of Knockakishaun to its modest summit cairn.

This route was a 4.4km round trip with 308 metres of ascent. Linkback: https://mountainviews.ie/summit/853/comment/20026/