The NCN route 68 - the Pennine Cycleway actually starts in Derby city. It runs from the back of the railway station along Roundhouse Road initially, before joining with NCN6 at the roundabout to follow the river into the city centre. After crossing Exeter Bridge it joins NCN route 54 to run through the city and then along the Mickleover Greenway before the 54 branches off southwards towards Burton.
See http://www.opencyclemap.org/ for details
It is signed as the 68 (along with signage for 6 and 54 where the routes co-incide).