The sun and his dog
Pentre Ifan cromlech, a prehistoric burial chamber, looks especially magnificent as the sun sets over the sea and on this occasion there was a bonus: a sun dog, seen on the right as a bright spot of coloured light. It's a meteorological phenomenon caused by refraction from ice crystals in the atmosphere and can be visible as a parhelion all around the lowering sun or a single spot that follows (dogs) it as it sinks.
That's the technical explanation anyway. Who knows what our ancient ancestors might have thought of it - a sign, a portent or simply an excuse for a party?