Isle of Lewis, Scotland, 1999
The Neolithic standing stones at Callanish are an enigma. The plan combines a circle which isn't round, with a cross which isn't square.
Construction commenced about 45 centuries ago, and the people who built the complex quarried large blocks of Lewissian Gneiss, with natural patterns and colours.
As observed from Callanish, the full moon in summer skims just below the horizon, before briefly emerging in a notch between two hills.