Archaeo-optics in Orkney Day 13: Thoughts at Cuween Hill

As it happened, the sun only made a rather understated appearance. But the time spent waiting gave us chance to think about our previous observations, and to photograph details of the monument.

Even in our absence, the passage cairn of Cuween Hill acts like a gigantic camera. The coloured area to the left of this side cell shows where daylight entering through the passageway falls, naturally 'exposing' an area of green (Photo: Aaron Watson)

Inside this side cell, the reach of natural daylight is restricted. Two shadowed areas are separated by this distinct patch of light (Photo: Aaron Watson)