I’ve lead quite a few rides around the Salisbury area for Newforce.
We often start at Whiteparish and loop up through Bentley Wood (some nice singletrack in there), Winterslow, picking up the Monarchs Way to Broughton Down, Tytherley, Lockerley and back via Dean Hill. You could pick this loop up via the Monarchs way from Old Sarum
I’ve also done some great rides to the North of this loop, again off the Monarch Way but heading up to loop round the Wallops, Palestine, Georgia, Oklahoma (no, i’ve not flicked the page on the map!) Clatford Oakcuts, over towards teh river, Danebury Hill (Bivvied here in the snow once!)and back via Broughton.
In the other direction, there’s some good stuff around BroadChalke, between the Oxdrove and Compton Down, which could lead you on to CRanborne Chase.
So, plenty to do really!