📌 Pirnmill Hills, Isle of Arran
★★★★
The westerly Pirnmill Hills are the highest summits on the Isle of Arran outwith the Goatfell Range. Although overshadowed (literally) by their more popular neighbours, they are wonderful hills in their own right and would be a popular walking destination if found anywhere else in southern Scotland. The main summits (two on Beinn Bharrain, plus Beinn Bhreac to the north) are characterised by whaleback ridges and fine coires; they also offer superb 360° views across the rest of Arran and the Kintyre peninsula. This circuit traverses the range before descending via the idyllic Coire Fionn Lochan, which makes a popular walk even by itself.
📷 Chronological photo guide
Woodland ascent 
Beinn Bharrain from the approach 
Allt Gobhlach 
Approach to the westernmost ridge 
Ascent to Casteal na h-Iolaire 
Rest of the Pirnmill Hills from the approach to Casteal na h-Iolaire 
Casteal na h-Iolaire summit 
View south along Arran’s west coast 
Coire Roinn 
Beinn Bharrain (Mullach Buidge) summit, Beinn Bhreac beyond 
Mullach Buidhe northwest ridge 
Loch Tanna & the Goatfell Range 
Glen Scaftigill 
Glas Choirein & ridge to Beinn Bhreac 
Beinn Bharrain from the ascent to Beinn Bhreac 
Glen Catacol 
Beinn Bhreac summit 
653m north top 
View back over the range 
Goatfell Range 
Coire Fhionn Lochan 
Coire Fhionn Lochan 
Descent to Thundergay 
Coast road return 
Pirnmill
🌍 Location
📌 Start / finish on the coast road, Pirnmill village centre, Isle of Arran
🧭 O.S. Grid Reference: NR 872442
🛰️ GPS coordinates: 55.644291,-5.383018
🚌 Infrequent bus to Pirnmill
🚗 Car park (gets full) or more options nearby
📝 Key info
▶ 15 km / 9 mi | ▲ 960 m | ⌛ 6-7 hr
Features: 🏠 Pirnmill; △ Casteal na h-Iolaire (717 m); △ Beinn Bharrain / Mullach Buidhe (721 m, “Torbett”); △ Beinn Bhreac (711 m); 💧 Coire Fhionn Lochan
⬤ Tough | Rough path for most of route, but pathless at times including for ascent of ridge to Caisteal na h-Iolaire. Boggy parts on ascent. Descent beyond Coire Fhionn Lochan is on a much better path, then minor road for return.
Download file for GPS➡️ Anticlockwise circuit: start & Pirnmll – cross Allt Gobhlach at 260m by weir – ridge west of Coire Roinn – Casteal na h-Iolaire – Beinn Bharrain / Mullach Buidhe – Beinn Bhreac – 653m north top – bealach south of Meall Bhig – Coire Fhionn Lochan outflow – Mid Thundergay – start via coast road
🥾 On our last visit
Wildlife: Sheep, lambs & frogs on the hill, red squirrel at Thundergay. Mute swans, curlews, oystercatchers & seagulls for coastal section.
Weather: Dry with some sunshine, especially on lower areas. Temperature in low teens, rising a bit. Chilly northerly breeze, summits intermittently in fog.
July 2022
