Take the N56 N from Letterkenny tand then go right onto the L5912 signed for Calhame. After 1.2km take a minor road on the right C181157 A. The tarred surface ends abruptly 250m along. and the road beyond this point is not driveable. Park and follow the now rough track for about 1km to a point where the tarmac surface returns and where a gate on the right C1901215390 B leads on to a narrower but good stone track. Follow this W uphill to a cross track junction, and either continue straight on or go right. Both routes lead up to the Trig Pillar marking the top of the hill. A short out and back trip of 3km to a fine viewpoint NE across Lough Swilly to Inch Top and the hills on Inishowen and SW over Letterkenny to the distant tops of the Bluestacks. Knockbrin can also be approached from the R245 between Letterkenny and Ramelton by taking a minor road NW from C205145 C and following it along through a cross roads to C1901215390 B and the gate giving access to the hill, already described above. Linkback: https://mountainviews.ie/summit/1203/comment/15447/