From the field that brought you cows.
A basic site plan altered to show an arc of possible positions for the fourth stone, which would probably have been located at the east of the conjectured circle. A position here would keep all stones with their long axes parallel to, and paired on either side of, a line running northeast to southwest.
Image credit: Modified by gjrk from Burl (BAR 195 1988) and O’Nuallain (JRSAI 114 1984)
