Thanks all.

The hill of Lugg (the one that the sun rises over) has a Neolithic henge in the middle of the plantation, which had a timber circle inside it (excavated in the 50s I think). I had wanted to watch from there, but the trees are too high to see the coast.

I'm kinda glad that I did go where I went now. I'm sure the cairn and passage tomb are there because of this alignment.