Green Belt land has been established around built-up areas in England since 1947 with the aim of defining and limiting the boundaries of a community and preventing urban sprawl.
Only Green Belt land in Hertfordshire is shown and this land extends to the west and south beyond what is shown on this map.
The only Green Belt land within the area contained by the Bishop's Stortford bypass comprises an area centered on Thorley.
Former Green Belt land between the the north of the town and bordered by the bypass was re-designated as Areas of Special Restraint Map in 1991.