When parking the car at the Cladh Hallan Graveyard, returning from Eriskay, car park I noticed a mound, which I presumed was once upon a time an island.
It turned out to be the scant remains of a dun, from the car park look east and walk in a straight line, we had returned from the roundhouses and simply kept going a short distance further.
It would be wrong to say all traces have been removed - several stones remain as well as the mound. One thing I did notice was the level of water in the nearby Loch Hallan - it was very low. Answers to that would explained during a visit to another site.