Question: Little Heath Pit is part of an estate situated in what Area of Outstanding Natural Beauty?
Context: Ashridge is a country estate and stately home in Hertfordshire, England in the United Kingdom; part of the land stretches into Buckinghamshire and it is close to the Bedfordshire border.  It is situated in the Chiltern Hills, an Area of Outstanding Natural Beauty, about 2 mile north of Berkhamsted and 20 mile northwest of London.  Surrounding villages include Aldbury, Pitstone, Ivinghoe, Little Gaddesden, Nettleden, Frithsden and Potten End. An Area of Outstanding Natural Beauty (AONB) is an area of countryside in England, Wales or Northern Ireland which has been designated for conservation due to its significant landscape value.  Areas are designated in recognition of their national importance, by the relevant public body: Natural England, Natural Resources Wales, or the Northern Ireland Environment Agency.  In place of AONB, Scotland uses the similar national scenic area designation.  Areas of Outstanding Natural Beauty enjoy levels of protection from development similar to those of UK national parks, but unlike with national parks the responsible bodies do not have their own planning powers.  They also differ from national parks in their more limited opportunities for extensive outdoor recreation. Little Heath is a district in the London Borough of Redbridge.  To the east is Chadwell Heath in the London Borough of Barking and Dagenham, after which it was modelled.  The postcode for the area is RM6.  Little Heath School is based in the area.  East London Transit route EL3 terminates at Little Heath. Little Heath Pit is a 0.3 hectare geological Site of Special Scientific Interest near Potten End in Hertfordshire.  It is part of the Ashridge Estate, owned by the National Trust, and the local planning authority is Dacorum Borough Council.  It is listed in the Geological Conservation Review. The Haven, Aldeburgh is a 20.2 hectare Local Nature Reserve in Aldeburgh in Suffolk.  It is owned by Suffolk Coastal District Council and managed by the Suffolk Coast and Heaths Area of Outstanding Natural Beauty.  It is in the Leiston - Aldeburgh Site of Special Scientific Interest and Suffolk Coast and Heaths Area of Outstanding Natural Beauty. The Isle of Wight Area of Outstanding Natural Beauty is an Area of Outstanding Natural Beauty (AONB) on the Isle of Wight, England's largest offshore island. The South Devon Area of Outstanding Natural Beauty (AONB) covers 337 square kilometres, including much of the South Hams area of Devon and the rugged coastline from Jennycliff to Elberry Cove near Brixham.  The purpose of an Area of Outstanding Natural Beauty is to conserve and enhance the area's natural beauty.  In South Devon this includes: undeveloped coastline, estuaries, geological and geomorphological features, expansive panoramic views, ancient agricultural field pattern, Devon banks, areas of high tranquility, dark night skies and natural nightscapes, historic features, green lanes, well known cultural associations, picturesque villages and hamlets.  South Devon AONB was formally designated in August 1960 under the National Parks and Access to the Countryside Act 1949 (South Devon AONB Management Plan 2009-14).  The highest point in the AONB is Blackdown Camp at 199 metres above sea level. The North Devon Coast was designated as an Area of Outstanding Natural Beauty in September 1959.  The AONB contributes to a family of protected landscapes in the Southwest of England and a total of 38% of the region is classified by the International Union for the Conservation of Nature as Category V Protected Landscapes.  The twelve Areas of Outstanding Natural Beauty extend to 30% of the region, twice the proportion covered by AONBs in England as a whole and a further two National Parks, Dartmoor and Exmoor, cover an addition 7%. Dunwich Forest is an area of forest and lowland heath around 1 mi north-east of the village of Dunwich in the English county of Suffolk.  The forest covers an area of around 9 sqkm and was originally planted by the Forestry Commission.  The forest is within the Suffolk Coast and Heaths Area of Outstanding Natural Beauty and is in the area known as the Suffolk Sandlings.  South of the reserve is the National Trust property of Dunwich Heath, one of the largest remaining areas of lowland heath on the Suffolk coast, and the RSPB reserve at Minsmere.  To the north and east of the forest are Dingle Marshes, part of the Suffolk Coast National Nature Reserve. The Cornwall Area of Outstanding Natural Beauty covers 958 sqkm in Cornwall, England, UK; that is, about 27% of the total area of the county.  It comprises 12 separate areas, designated under the National Parks and Access to the Countryside Act 1949 for special landscape protection.  Of the areas, eleven cover stretches of coastline; the twelfth is Bodmin Moor.  The areas are together treated as a single Area of Outstanding Natural Beauty (AONB).
Answer: Chiltern Hills