²⁶Moore, Sam. "Cairn G Roof-Box" Message to the author. 22 Oct. 2013. E-mail.
Sam Moore writes, "If you look at the internal arrangement of the chambers within cairns G and K, which you have done on VR you will see that, unlike any other passage tombs that I have seen, the building construction of the lintel stones above the entrances to the chambers forms a void above each of the chamber entrances...So this particular architectural feature is also present in the entrance to cairn G, which Martin Byrne and others have suggested acts as a roof box similar to that in Newgrange. However, being cautious, it might merely be an architectural feature that allows the ceiling corbels to spring from along the passage, and it may originally have been covered in cairn material with no opening whatsoever. " Moore references a photograph of myself (Howard Goldbaum) emerging from Cairn G, taken in 1979, that I provided to him: "The photograph of you at cairn G...shows denuded corbels very clearly before the cairn was 'tidied up' by the OPW. Alternatively it could be a 'portal' for ancestral spirits to come and go and may have been blocked and opened at certain times, but this is impossible to prove."
As part of the basis for his skepticism regarding the roof-box, Moore also points to the alignment at Cairn G: "The astronomical alignment at G is imperfect and the sun comes into G obliquely for a considerable period over the solstice. Cairn H is more accurately aligned. Given the orientation spread of the 14 cairns with identifiable passages NW to NE there is a high statistical probability that the sun will come in to some of them around the solstice." (Moore, Sam. "Cairn G Details" Message to the author. 4 July. 2013. E-mail.)