An area of undeveloped land encircling a town, restricting development in the semi-rural areas beyond the built-up zone. The amount of new building is restricted although by no means completely banned. An early green belt was set up in the 1950s around Greater London, in order to limit the spread of suburbs. Other cities have followed this example: in Beijing, all the land in the ‘green belt’ was forced to keep its status in 2004 without any changes until 2020. ‘Under this policy, the trend of central city to form a big pancake would be stopped, while the sub-cities in the region would develop very fast with many small and medium “pancakes” forming outside the 6th Ring Road’ (He et al. (2006) Appl. Geog. 26, 3–4). Cullingworth calls green belts ‘the first article of the British planning creed’, but Nadin argues that they ‘have become an outmoded and largely irrelevant mechanism for handling the complexity of future change in the city’s countryside’ (both in J. Cullingworth and V. Nadin 2002).