Cairn na Burgh Beag

Cairn na Burgh Beag is a small grassy island in the Treshnish Isles, part of the Inner Hebrides off Scotland’s west coast. It lies at the north-eastern end of the group alongside its larger neighbour, Cairn na Burgh Mòr. Both islands are flat-topped remnants of ancient lava flows, their edges marked by steep cliffs. A notable feature is Cairnburgh Castle, whose defences stretch across both islands, including a guard-house and a well on the smaller isle. The larger island holds the main castle buildings, guarding the entrance to Loch Tuath on Mull’s west coast. Historians link the site to a 14th-century castle called Iselborgh, granted by David II to John of Islay. Duncan and Brown argued Iselborgh was another name for Cairn na Burgh Beag, supported in 1980 by the Royal Commission on the Ancient and Historical Monuments of Scotland. Other locations have also been suggested for Iselborgh, leaving its exact site debated. The islands’ volcanic origins and shared defences make them unusual in the Hebrides. Visitors find two flat-topped islands rising from the sea, their cliffs framing narrow grassy plateaus. The smaller island holds the castle’s outworks, while the larger carries the main ruins. The setting offers views across the Treshnish Isles and towards Mull’s coastline. The islands’ volcanic past is visible in their layered rock faces and flat summits. The contrast between the green grass and dark cliffs creates a striking landscape. The remains of the castle show how the two islands once worked as one stronghold.