One of four outlying stones called the Station Stones, of which only two remain. They formed a rectangle around the central monument with its sides in the ratio of 5:12.
The short sides of the Station Stone rectangle are aligned to the primary solstitial axis (summer sunrise to winter sunset). The long sides are aligned to the southernmost possible moonrise and northernmost possible moonset during the year of the Major Lunar Standstill, which occurs every 18.61 years.
The positions of the missing two Station Stones (92 and 94) are indicated by modern stone and steel markers in the turf - one on the South "Barrow" and the other on the North "Barrow".
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Estimated above ground weight: 1.34 tons