The DSNR is a disused rail line between Didcot Parkway, through the rolling downlands past Harwell, Ilsley and Compton to Newbury, then on towards Southampton. The land has been built upon, filled in, or ploughed away. Following the line is often a case of research on OS maps observing the obvious cuttings and bridges. I’ve walked the route from Didcot to Newbury, but have only documented half of the journey: the first an easy route from Didcot to Upton and the second; the best part of the walk to me, from Upton to Compton. Fascinating the engineering that went into the line. It must have been a game changer for the villages on the route when the line was open.
You can find out a lot more from the Didcot, Newbury and Southampton Railway Revival site.
For background reading look at the following: