In many ways the most interesting places in the Caha Mountains are to be found at the edges where glacial action has cut deep valleys and steep cliffs. On the northern side of the Cahas, the valley of Glenrastel is best known, however its smaller cousin Glentrasna is worth a visit. Knockreagh is the northern outlier of the summits circling Glentrasna.

One obvious way to reach it is by leaving the R571 road (Tuosist to Lauragh) at V805605 C. Walk up the track which goes at least as far as is marked on the 1:50k map. The track deteriorates badly towards the end, nevertheless the time I visited there were distinct tractor tracks almost to the end.
The summit is a great vantage point for views SW along the north Beara coast.
Two isolated peaks stick up out of the low plain before the inlet of Kilmakilloge Harbour. They are visible in the photo as the nearer dark lump (Knockanoughanish) and, just visible, the top on the skyline at the right (Knockatee). Though both under 400m these distinctive summits are very obvious from many parts of the Glentrasna circuit. Beyond stretches the coastline, not so visible on the murky day this picture was taken. To the left the rising ground leads to the delights of Tooth Mountain (590m) and Coomacloghane (599m). Linkback: https://mountainviews.ie/summit/456/comment/2235/

En route to Knockreagh from Coomnadiha one happens upon this spectacular view of Cummeenadillure Lough (point V 833 607 D) Also spotted a couple of herds of wild goats nearby. Linkback: https://mountainviews.ie/summit/456/comment/4040/

Some photos to add of the mountains, valleys & harbours mentioned in Simon's comment on Knockreagh Linkback: https://mountainviews.ie/summit/456/comment/2237/

Around 350m north of the summit of Knockreagh there's a sharp drop to Lough Napeasta seen as the nearer lake in the picture. Further away two of the Clonee lakes (Upper on the right, middle to the left) are visible as is the Uragh wood (between L. Napeasta and Upper Clonee Lough). This wood and surrounds are a Nature Reserve designated in 1982 and a distinctive habitat listed on Annex I of the E.U. Habitats Directive. It is famous for semi-natural oak and birch. Apparently the Kerry slug can be found and a colony of bats in a deserted house further east and up the valley (right in the picture).

Another way up Knockreagh that is mentioned (though I haven't tried it) starts on the Beara Way at
V831 638 E between the Middle and Upper Clonee Loughs. The Beara Way uses a track which stops north of Knockgarrane, the spur to the left of Lough Napeasta. From the end of the track ascend Knockgarrane. Although the mist and shadowless light softens the impact, note the extremely corrugated nature of terrain of Knockgarrane above the lake described by David Herman [Hillwalker South Kerry and West Cork] ".. the slabs rising from the shore look like a steeply rising ploughed field." He even has a sketch of them. Linkback: https://mountainviews.ie/summit/456/comment/2240/

Some photos to add of the mountains, valleys & harbours mentioned in Simon's comment on Knockreagh Linkback: https://mountainviews.ie/summit/456/comment/2238/