Follow the same directions as Mark, and stop at the same place. The way over to the cairn was kinder to me, there was hardly any seaweed and in any case I'd had my troubles for the earlier at Ardnamonie.
Unlike the previous two sites I could get to this one and there is quite a lot to see. At 20m wide, damage by both humans and erosion has led to stones falling all around the site 13 in total, some of which might be capstones. Thanks to robbing the chamber can be seen and thanks to the robbing its difficult to tell if there are three areas / compartments. Two can be certainly seen, of the third only two stones remain standing.
I attempted to reach Sig More cairn from the beach however the cairn was surrounded by a carpet of seaweed which deterred me from investigating further. The profile of the mound is a classic cairn with large kerb stones visible.
Directions: The cairn is located on the N coast of South Uist. Half a mile before the South Uist Benbecula Causeway turn R to Aird Mhor/Ardmore just after passing a roadside shrine. Follow the single track road to park at a dead end at Rhughasinish (NF81394517). Walk back along the track for c. 300 yards to reach a house. Head NW across rough ground for c. 500 yards to reach the coast. The cairn is accessible from the coast depending on the tide level.
This Hebridean Passage Grave sits on a small tidal islet. In the neolithic the three islands were one landmass and the watery landscape which characterises the Uists today did not come into effect until about 2000 bce.
Traces of the passage and chamber on the islet with several peristaliths visible at tide level.
Access. Parking ok on the approach road. Through one gate then over a tricky barbed wire fence to the shore.