The English Civil War at Longhedge, near Old Sarum
I’ve written before about the military on this site, in that case the WW2 remains. This is a feature from a slightly different period.
This roughly square feature, with further squares on the corners, was first seen in the geophysical results when this housing site was first considered for development. At that point, no-one was quite sure what it was. Although a Civil War date was considered, it was also possible that this feature was associated with the WW2 features that surrounded it.