green belt
Area surrounding a large city, officially designated not to be built on but preserved where possible as open space for agricultural and recreational use. In the UK the first green belts were established from 1938 around conurbations such as London in order to prevent urban sprawl. New towns were set up to take the overspill population.
The term generally refers to the ‘outer ring’ proposed in the Greater London Plan by Patrick Abercrombie; Abercrombie envisaged a static population in this ring, with new towns beyond it.
