A designation for land around certain cities and large built-up areas, which aims to keep this land permanently open or largely undeveloped. The purposes of the green belt are to:
- check the unrestricted spread of large built up areas
- prevent neighbouring towns from merging
- safeguard the countryside from encroachment
- preserve the setting and special character of historic towns
- assist urban regeneration by encouraging the recycling of derelict and other urban land