The Environmentally Sensitive Areas were introduced in 1987 to offer incentives to encourage farmers to adopt agricultural practices which would safeguard and enhance parts of the country of particularly high landscape, wildlife or historic value. The scheme has now closed to new applicants. Defra introduced a new Environmental Stewardship Scheme on 3 March 2005 which supersedes (with enhancements) the Environmentally Sensitive Areas and Countryside Stewardship Schemes. There are 22 ESAs in England, covering some 10% of agricultural land.
More information about the ESAs can be viewed here.Full metadata can be viewed on data.gov.uk.