I was apprenticed to Bricklaying by my father in the early 1950s and I detested the job.  As a result on a nice summer day I sometimes played truant taking my lunch box along Chiswell Valley which is on the Western side of what was then the Southern bypass and just enjoyed the utter peace of the area.

Can anyone offer any information on that valley?

I think the area is Chilswell (not Chiswell) and the valley goes up towards Boar's Hill. I have yet to go up there with a camera, but there should be superb views of Oxford and the Dreaming Spires from the top of the hill. There is a guide to the walk at :

 http://www.oxfordshire.gov.uk/cms/content/chilswell-valley-circular-walk