One of the last walks I did before leaving for Australia was over the old Midland line from Monsal Dale over the viaduct, through the tunnels(still open then) to Millers Dale, I seem to remember the track being lifted(not sure, August 1971?) but the ballast still in situ. I wore thin soled desert boot and the next day both feet were covered in huge blisters!!. The views were absolutely spectacular----I will never forget that walk. Sad though, only a few years earlier we used to sit at Monsal Dale by the river and watch Jubilees, Black Fives etc. thundering over the viaduct.
Rgds.Mike