A small rocky island which represents the most northeasterly of the Treshnish Isles in the Inner Hebrides, Cairn na Burgh Beg (also Cairnburgh Beg) is one of two islands which guard the entrance to Loch Tuath on the west coast of Mull. Immediately to the west is the slightly larger Cairn na Burgh More. These grassy islands are both remnants of ancient lava flows, and have a distinctive profile: flat-topped and trimmed with cliffs. Cairn na Burgh Beg has an area of 1.2 ha (3 acres) and rises to 22m (72 feet). There are the remains of a castle here but landing is difficult due to strong tidal races.
Along with the other Treshnish Isles, Cairn na Burgh Beg is owned and managed by the Hebridean Trust.