Question: A county in the East of England has one of the largest self-suffcient communities which posses 1500 acres of local land. What is this called?

Context articles: Big Bend Power Station
Land Trust Alliance
Adams Homestead and Nature Preserve
Quex Park
Bremo Historic District
Frampton Court
Burton in Lonsdale
Conservation easement
Essex
Stratford Langthorne Abbey

Big Bend Power Station is a major coal-fired power plant, located across Tampa Bay from Tampa, Florida on nearly 1500 acres in southeastern Hillsborough County, close to Apollo Beach.
 It is owned and operated by TECO Energy.
 Three similar units (each 445.5 MWe nameplate capacity) were launched in the early 1970s, followed by a newer 486-MWe unit 4 in 1985.
The Land Trust Alliance, originally formed in 1982 as the Land Trust Exchange, is a national conservation organization representing more than 1,700 land trusts across the United States.
 The organization describes its objectives as working to increase the pace and quality of conservation by advocating favorable tax policies, training land trusts in best practices, and working to ensure the permanence of conservation in the face of continuing threats.
 The Land Trust Alliance is based in Washington, DC.
 As of December 2010, national, regional and local land trusts have conserved a total of 47 million acres (190,000 km) of land in America.
Adams Homestead and Nature Preserve is a South Dakota state park in Union County, South Dakota in the United States.
 The former Stephen Searls Adams homestead property dates to 1872 and covers 1500 acres on the Missouri River.
 The property was donated in 1984 and the park was established in 1997.
 The park is open for year-round recreation including hiking and cross country skiing.
Quex Park itself is 250 acre of parkland and gardens plus a further 1500 acres of farmed land, with Quex House and other buildings situated just south-east from Birchington-on-Sea in Kent, England.
 It houses the Powell-Cotton Museum, and the Waterloo tower, a secular bell tower.
Bremo, also known as Bremo Plantation or Bremo Historic District, is a plantation estate covering 1500 acres on the west side of Bremo Bluff in Fluvanna County, Virginia.
 The large mansion at Upper Bremo was designed by owner John Hartwell Cocke in consultation with John Neilson (c.1770 - 1827), the designer of Thomas Jefferson's Monticello.
 The estate includes two smaller residences built at Lower Bremo and Bremo Recess.
Frampton Court is a Grade I listed country house and estate of about 1500 acres in Frampton-on-Severn, Gloucestershire, England.
 It has been owned by the Clifford family since the 11th century.
 The main buildings are the 18th century Frampton Court and, on the opposite side of the village green, Manor Farm.
 The gardens at Frampton Court have a Gothic orangery and ornamental canal in the style of William Halfpenny.
 The two houses, barn and orangery are all Grade I listed buildings in their own right, while the Gatepiers and Gates are Grade II* listed.
Burton in Lonsdale is a village and civil parish in the Craven district of North Yorkshire, England, close to the border with Lancashire.
 It is in Lonsdale (the River Lune valley and its tributaries).
 According to the 2001 census it had a population of 621 decreasing to 579 at the 2011 Census.
 The parish is approximately 1500 acres (6 km²) in area and has many farms – dairy, beef and sheep.
 Little is grown, except grass to feed the animals.
In the United States, a conservation easement (also called conservation covenant, conservation restriction or conservation servitude) is a power invested in a qualified private land conservation organization (often called a "land trust") or government (municipal, county, state or federal) to constrain, as to a specified land area, the exercise of rights otherwise held by a landowner so as to achieve certain conservation purposes.
 It is an interest in real property established by agreement between a landowner and land trust or unit of government.
 The conservation easement "runs with the land," meaning it is applicable to both present and future owners of the land.
 As with other real property interests, the grant of conservation easement is recorded in the local land records; the grant becomes a part of the chain of title for the property.
Essex is a county in the East of England immediately north-east of London and is one of the home counties.
 It borders the counties of Suffolk and Cambridgeshire to the north, Hertfordshire to the west, Kent across the estuary of the River Thames to the south and London to the south-west.
 The county town is Chelmsford, which is the only city in the county.
Stratford Langthorne Abbey, or the Abbey of St Mary's, Stratford Langthorne was a Cistercian monastery founded in 1135 at Stratford Langthorne — then Essex but now Stratford in the London Borough of Newham.
 The Abbey, also known as West Ham Abbey as it lay in that parish, was one of the largest Cistercian abbeys in England, possessing 1500 acre of local land, controlling over 20 manors throughout Essex.
 The Abbey was self-sufficient for its needs and wealthy besides; some of this wealth came from the ecclesiastic mills grinding wheat for local bakers to supply bread to the City of London.
 This later led to competition with the Guild of Bakers, who sought powers to levy a toll on loaves entering the City at Whitechapel.