In 2017, the line of the footpath (SALS6) that runs alongside Parsonage Farm was officially changed and the slightly amended route recorded on Wiltshire Council's Definitive Map. Unfortunately some visitors and walkers have been lead astray by relying on out-of-date Ordnance Survey (OS) maps and have found themselves on private land.
The right-of-way runs parallel to Stratford Road and passes the barn (pictured) to the eastern (Old Sarum) side. There isn't any access from Stratford Road at this point.
If you've walked to Stratford Road from Mill Lane, either turn left to access the path from Gradidge Lane (just before the church) or turn right and take the footpath just beyond Dairy Cottage (SALS23) and then within a few yards, turn left.
There are several suggestions for local walks on this webpage: https://www.stratfordsubcastle.org.uk/walks-2
More about Rights of Way https://www.stratfordsubcastle.org.uk/rights-of-way
Streetmap.co.uk provides free access to OS Maps for personal use.