Question: Little Heath Pit is part of an estate situated in what Area of Outstanding Natural Beauty?

full_context: Document 1: Roughdown Common: Roughdown Common is a 3.6 hectare biological Site of Special Scientific Interest in Hemel Hempstead in Hertfordshire. The planning authority is Dacorum Borough Council. The site is Common land, and it is owned by the Box Moor Trust having been officially brought by the trust in April 1886 from the Dean and Chapter of St Paul's. It is part of the Chilterns Area of Outstanding Natural Beauty. The Common is a steeply sloping chalk hill in south Hemel Hempstead.
Document 2: Colney Heath Local Nature Reserve: Colney Heath Local Nature Reserve is a 22.5 hectare Local Nature Reserve in Colney Heath in Hertfordshire. It is owned by St Albans City Council and managed by Colney Heath Parish Council. The site was acquired in the 1950s and 1960s, and it is a Hertfordshire Heritage Site.
Document 3: Ashridge: 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.
Document 4: Watling Chase Community Forest: Watling Chase Community Forest is an area of 72 square miles located in north London and south Hertfordshire around the towns of Potters Bar, Radlett, Borehamwood and Barnet. It includes Aldenham Country Park, Scratchwood, Moat Mount Open Space and the Watling Chase Timberland Trail, a waymarked walk of 16 kilometres.
Document 5: Frithsden: Frithsden is a small hamlet in Hertfordshire, England. It is located in the Chiltern Hills, about two miles north of Berkhamsted, to which it belongs. It is in the Dacorum Ward of Nettlden with Potten End.
Document 6: Potten End: Potten End is a village in west Hertfordshire, England. It is located in the Chiltern Hills, two miles east-north-east of Berkhamsted, three miles north west of Hemel Hempstead and two miles south east of the National Trust estate of Ashridge. Nearby villages include Nettleden, Great Gaddesden and the hamlet of Frithsden. The joint Parish Council for "Nettleden with Potten End CP" administers under Dacorum Borough Council.
Document 7: Wigginton, Hertfordshire: Wigginton ("Wigentone" - 1086) is a large village and civil parish running north-south and perched at 730 ft on the edge of the Chiltern Hills and aside the border with Buckinghamshire. It is part of Dacorum district in the county of Hertfordshire. The nearest towns are Tring in Hertfordshire (1.5m NW) and across the other side of the A41, Chesham (6m S) and Wendover (6m W), both in Buckinghamshire. Adjacent to the main village is the settlement of Wigginton Bottom where a number of farmworkers cottages were built during the 19th century.
Document 8: Ridge, Hertfordshire: Ridge is a village and civil parish in the Hertsmere borough of Hertfordshire, situated between Potters Bar and Shenley. At the 2011 Census the village was a civil parish in its own name. The population of the parish was 177. It has a church, St Margaret's; a children's playground; and the Old Guinea public house, which serves food on most days. The village holds an annual fete on the August bank holiday. Ridge is surrounded by countryside with numerous public footpaths. In 1926, the parish boundary between Ridge, Hertfordshire, and South Mimms, Middlesex, was subject to a minor adjustment.
Document 9: Hertfordshire: Hertfordshire ( ; often abbreviated Herts) is a county in southern England, bordered by Bedfordshire to the north, Cambridgeshire to the north-east, Essex to the east, Buckinghamshire to the west and Greater London to the south. For government statistical purposes, it is placed in the East of England region.
Document 10: Little Heath, London: 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.
Document 11: Little Heath Pit: 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.
Document 12: Totternhoe Knolls: Totternhoe Knolls is a 13.1 hectare Site of Special Scientific Interest (SSSI) in Totternhoe in Bedfordshire. It is also a Local Nature Reserve, and part of the Chilterns Area of Outstanding Natural Beauty. The site is owned by Central Bedfordshire Council and leased to the National Trust. Most of the site is maintained jointly by the National Trust and the Wildlife Trust for Bedfordshire, Cambridgeshire and Northamptonshire (WTBCN), and is part of the WTBCN Totternhoe nature reserve, which also includes Totternhoe Chalk Quarry and Totternhoe Stone Pit. The SSSI also includes Totternhoe Castle, the earthworks of a Norman motte-and-bailey castle which is a Scheduled Monument.
Document 13: Nettleden: Nettleden is a village in Hertfordshire, England. It is in the Chiltern Hills, about four miles north-west of Hemel Hempstead, near Little Gaddesden, Great Gaddesden and Frithsden. Nettleden with Potten End is a civil parish in Dacorum District.
Document 14: College Lake nature reserve: College Lake is a 65 hectare nature reserve in a former chalk quarry in Pitstone in the Aylesbury Vale district of Buckinghamshire. It is one of the flagship reserves of the Berkshire, Buckinghamshire and Oxfordshire Wildlife Trust, and it has an information centre, education facilities, a café, toilets and a shop. It is in the Chilterns Area of Outstanding Natural Beauty. The area east of the lake is a geological Site of Special Scientific Interest called Pitstone Quarry.
Document 15: Totternhoe Chalk Quarry: Totternhoe Chalk Quarry is a 13.4 hectare biological Site of Special Scientific Interest in Totternhoe in Bedfordshire. Part of it lies in Totternhoe nature reserve, which is managed by the Wildlife Trust for Bedfordshire, Cambridgeshire and Northamptonshire. The site is part of the Chilterns Area of Outstanding Natural Beauty.
ground_truth: Chiltern Hills