The aim of this part-route is to visit some attractive features, with relaxing views and scenery, of rural-feel Oxford that only people on bikes (or on foot) can reach.  It's countryside within the city.  Included are 

• the Victorian footbridge over the London Road, built for the Morrell family in 1877.  www.headington.org.uk/history/listed_buildings/headhillhall_bridge
• the track across the top of South Park, with a fabulous view westwards over Oxford City.  It's next to a gin distillery.  An excellent children's playground is adjacent to the exit at Warneford Lane
• the improved cycleway along Warneford Lane, segregated from motor traffic by protective wands 
• a busy road junction between Old Road, Warneford Lane, Roosevelt Drive and Gipsy Lane.  Use the pedestrian signal if you're not confident about waiting to turn right across oncoming traffic
• Warneford Meadow (wikipedia), saved from housing development by its Friends, who successfully got it designated as a Town Green.  Stop to enjoy the apple orchard on its north-western boundary or the Boundary Brook wildlife corridor on its eastern boundary www.headington.org.uk/history/misc/boundary_brook
• Southfield Road, which runs between playing fields belonging to Oriel and Jesus Colleges of Oxford University.  Good blackberries here in the autumn.
  The start-point on Pullen's Lane can be reached on a bike from many directions.  The finish on Barracks Lane is on the main East<>West cycle route through East Oxford, LCN4, that avoids cycling along the Cowley Road itself.
• History of Pullens Lane: www.headington.org.uk/history/streets/pullens_lane/origins.htm