Many of the country do say, that in the larger round [of stones] the sun, and in the lesser the moon, was worshipped by the old pagan inhabitants of these isles.
From Brand’s ‘A Brief Description of Orkney, Zetland, Pightland-Firth and Caithness’ (from I think 1701 originally, but I found it in ‘A general collection of the best and most interesting voyages and travels in all parts of the world’, which was put together by John Pinkerton in 1809 – you can read it on Google Books.)