Green Belts are designated areas of open land around cities where building is restricted. The Metropolitan Green Belt (MGB) has encircled London for over 60 years. Debate about the MGB has intensified in recent years. Many see it as a vital policy that guards against urban sprawl. Others argue it is a cause of the housing crisis. In the face these heated debates the LSE project, A 21st Century Metropolitan Green Belt has investigated what form the MBG should now take. This film summarises the research project's findings.