Aaaah thanks for the tip - I've done a bit of research and found it's actually Achmore (which is a problem for the metre of the song's lyrics!) - hard one to see - it's an unexcavated ruin - but amazing to look out across to the Calleach and see her heavy with child!

The song hopefully'll explore the triple-goddess in the landscape up there (cf. the three stones at Cnoc Filibhir Bheagh)

Cheers
Matt