Beinn Nuis, Beinn Tarsuinn, Cir Mhor and Glen Rosa Loop

This is one of Arran’s classic big mountain circuits: a rough, committing loop of about 18 km / 11.2 miles with around 1,100 m / 3,610 ft of ascent, linking Beinn Nuis, Beinn Tarsuinn and Cìr Mhòr before dropping back out through Glen Rosa. It is a difficult day with steep ground, long stretches of exposed ridge, loose and rocky sections, and a descent that can feel every bit as serious as the climb. The usual start is at the end of the public road by Glen Rosa Campsite, Glen Rosa, near Brodick, Isle of Arran, where parking is limited and often busy. (walkhighlands.co.uk)

From the trailhead, the route begins gently on estate track and path into Glen Rosa, with the great granite skyline of Arran building ahead. Early on, the walking is straightforward and gives you time to settle in before the harder mountain ground begins. Goatfell dominates one side of the view, while the sharper architecture of Cìr Mhòr and the ridges around it gradually come into focus deeper in the glen. This lower section is often the easiest navigation of the day; once you leave the glen floor and commit to the ridge, the outing becomes much more serious. (walkhighlands.co.uk)

Climb to Beinn Nuis

Most descriptions of this loop take the ridge on the west side of Glen Rosa first, climbing toward Beinn Nuis. The ascent is steep and sustained, gaining a large share of the day’s height in one push. Expect rough hill paths, eroded sections, wet ground after rain, and increasingly rocky terrain as you rise above the glen. Beinn Nuis stands at about 792 m / 2,598 ft, and although it is often overshadowed by its higher neighbours, it is a striking summit in its own right, with a steep-sided, pyramidal profile above Glen Rosa. (arranwildwalks.com)

The first few kilometres can feel deceptively manageable, but this is where pacing matters. In poor visibility, the line onto and along the ridge needs care, and strong winds can make the higher ground uncomfortable. HiiKER is the navigation tool to have loaded before setting out, especially because the terrain becomes more complex once the ridge narrows and the path grows fainter in places.

Ridge to Beinn Tarsuinn and Cìr Mhòr

From Beinn Nuis, the route continues along the ridge to Beinn Tarsuinn, the highest point of the loop at about 826 m / 2,710 ft. This section is one of the highlights of the day: broad mountain views, a real sense of height over Glen Rosa, and a more rugged, airy character than the approach suggests from below. The ridge is not a casual hillwalk in bad weather, though. There are rocky steps, uneven footing, and sections where route choice matters. (alltrails.com)

Beyond Beinn Tarsuinn, the traverse toward Cìr Mhòr becomes more dramatic. Cìr Mhòr is one of Arran’s best-known peaks and one of the island’s four Corbetts, rising to about 799 m / 2,621 ft. The mountain’s name is often translated as “great comb,” a good fit for its jagged outline. The surrounding skyline includes the famous Rosa Pinnacle and the rugged head of the glen, giving this part of the route a distinctly alpine feel by Scottish island standards. Some sections around Cìr Mhòr involve steeper, rockier ground and can require hands for balance; in mist, the descent lines and connecting paths are not always obvious. (walkhighlands.co.uk)

This is the point in the day where hikers should honestly assess conditions and energy levels. The loop is not especially long by distance, but the terrain makes it slow. On dry, calm days it is a superb mountain round; in wind, rain, or low cloud it becomes much more committing.

Descent through Glen Rosa

After Cìr Mhòr, the route drops back toward Glen Rosa and follows the glen out to the start. This descent is often where tired legs notice the difficulty rating most. Expect steep, rocky ground at first, then rougher mountain path easing into better tracks lower down. The return through Glen Rosa is scenic and more forgiving underfoot, but it is still a long walk out after the ridge. (alltrails.com)

Glen Rosa itself is one of Arran’s most celebrated landscapes, a broad glen framed