Here's my tuppence worth on this wonderfully-located but enigmatic site.
The circle of stones has one on the E facing slightly "into" the circle and, if the next one along had been present but the mirror image, they would have formed the shallow E-facing forecourt which is a common feature in Hebridean chambered cairns.
The large central stone would then be a backstone to the passage and chamber entered through this forecourt.
The only problem is that Audrey Henshall (who wrote two large volumes on the Chambered Tombs of Scotland) supports the view that it is a ruined building.
But what are Historic Scotland playing at? The signpost describes it as a homestead (which is what it is scheduled as) but the information board (one of the old ones) refers to it as a chambered cairn.
This is a great place, or rather has the potential to be much more. Looked after by Historic Scotland? I don't think so! With heather and grass climbing all over it again, its a crying shame this hasn't had more effort put in. There are some fantastic stones here with great shapes but slowly dissapearing. The OS report doubts that there was a cairn here, but I am sure to most folks you just have to look. Course there was! Anyway, it's well worth a look.
There are all sorts on the Western coast of Lewis. Most are ‘blink and you’ll miss it places’ such as the unsignposted Loch an Duna Broch, the remains of which lie on a small island linked to the mainland of the loch by a ever more waterlogged causeway. Theres another one on a loch just a few miles up the road. The loch at shader, itself overlooked by the remains of a chambered cairn known as Steinicleit.
Opposite Steinicleit (which could date from 3000BC) past the loch is the huge monolith of Clach an Truseil. An absolutely huge stone which now, I was reasonably surprised to note had a picnic bench not too far away from it.
Steinacleit (AKA Lower Siadar) Stone Circle and Cairn
From our great wee campsite at Siabost, we headed north east today up the A857 on our way to the Butt of Lewis, stopping of first at the massive Clach an Trushal, then this site. This is a very complex place- there are only about 5 upright stones, but loads of others and the remains of a (supposedly) chambered cairn in the centre of the circle. I dunno- it's a rather sad and disappointing place- I was mebbe hoping for a more grand stone circle- now it just looks very messy.
RCAHMS NMRS record no. NB35SE 2 at HY39625407 change of site description to homestead and field system dates from late 1980. Even Henshall only called the stone circle "alleged". On the other hand NB35SE 3 that was a standing stone is now scheduled as stone circle and enclosure!