Equinox Sunbeams in WKLB
Twice yearly, around the time of the Spring and Autumn Equinoxes, the rising sun sends a ray of light into this 5,650 year-old monument.
The spectacle is visible for a week or more either side of the actual Equinox and the light takes a slightly different course through the barrow each day.
Clear sunrises are not common: this was the only one of September 2013.
Video by Steve Marshall
