This had substantial ramparts made of stones with a timber frame, enclosing a large area and making good use of the natural defences of the hill-top.
This island, locally termed Eilean na Goar, is the most eastern and is bounded on all sides by precipitous gneiss rocks; it is the abode and nesting place of numerous sea birds. The flat surface on the top is 120 feet from the sea level, and the remains of the vitrified fort are situated on this, oblong in form, with a continuous rampart of vitrified wall five feet thick, attached at the SW end to a large upright rock of gneiss
This site was occupied in several periods, originally late Bronze age between 700 – 500BC. Firstly a simple farmstead which expanded to a blockhouse (fort) and then by a huge circular broch. A population of around 60 lived in this little fortress. Later, 2nd century occupation is shown when a wheelhouse was added.
Arka Unskel is 2½ miles ESE of Arisaig at NM693839 and has also been known as Ard Ghaunsgoik and Ard Ghamhgail. Described as on a promontory on the north side of Loch nan Uamh with a heavily vitrified wall.