||This article needs additional citations for verification. (April 2010)|
Chiltern Hills near Nettlebed
|Location||South East England|
|- location||Haddington Hill|
|- elevation||267 m (876 ft)|
|Plant||beech, bluebell, candytuft, woodruff|
|Animal||badger, muntjac, fallow deer, fox, kestrel, red kite, woodpecker|
The Chiltern Hills form a chalk escarpment in South East England. They are known locally as "the Chilterns". A large portion of the hills was designated officially as an Area of Outstanding Natural Beauty in 1965.
The Chilterns cover an area of 833 km2 (322 sq mi) and are 18 km (11 mi) at their widest and stretch 74 km (46 mi) in a southwest to northeast diagonal from Goring-on-Thames in Oxfordshire, through Buckinghamshire, via Dunstable Downs and Deacon Hill in Bedfordshire, to near Hitchin in Hertfordshire.
The boundary of the hills is clearly defined on the northwest side by the scarp slope. The dip slope, by its nature, merges with the landscape to the southeast. Similarly, the Thames provides a clear terminal to the southwest, whereas northeast of Luton the hills decline slowly in prominence.
The chalk escarpment of the Chiltern Hills overlooks the Vale of Aylesbury, and approximately coincides with the southernmost extent of the ice sheet during the Anglian glacial maximum. The Chilterns are part of a system of chalk downlands throughout eastern and southern England, formed between 65 and 95 million years ago, and comprising rocks of the Chalk Group and which also includes Salisbury Plain, Cranborne Chase, the Isle of Wight and the South Downs, in the south. In the north, the chalk formations continue northeastwards across north Hertfordshire, Norfolk and the Lincolnshire Wolds, finally ending as the Yorkshire Wolds in a prominent escarpment, south of the Vale of Pickering. The beds of the Chalk Group were deposited over the buried northwestern margin of the Anglo-Brabant Massif during the Upper Cretaceous. During this time, sources for siliciclastic sediment had been eliminated due to the exceptionally high sea level. The formation is thinner though the Chiltern Hills than the chalk strata to the north and south and deposition was tectonically controlled, with the Lilley Bottom structure playing a significant role at times. The Chalk Group, like the underlying Gault Clay and Upper Greensand, is diachronous.
During the late stages of the Alpine Orogeny, as the African Plate collided with Eurasian Plate, Mesozoic extensional structures, such as the Weald Basin of southern England underwent structural inversion. This phase of deformation tilted the chalk strata to the southeast in the area of the Chiltern Hills. The gently dipping beds of rock were eroded, forming an escarpment.
The chalk strata are frequently interspersed with layers of flint nodules which apparently replaced chalk and infilled pore spaces early in the diagenetic history. Flint has been mined for millennia from the Chiltern Hills. They were first extracted for fabrication into flint axes in the Neolithic period, then for knapping into flintlocks. Nodules are to be seen everywhere in the older houses as a construction material for walls.
Physical characteristics 
The highest point is at 267 m (876 ft) above sea level at Haddington Hill near Wendover in Buckinghamshire; a stone monument marks the summit. The nearby Ivinghoe Beacon is a more prominent hill, although its altitude is only 249 m (817 ft). It is the starting point of the Icknield Way Path and the Ridgeway long distance path, which follows the line of the Chilterns for many miles to the west, where they merge with the Wiltshire downs and southern Cotswolds. To the east of Ivinghoe Beacon is Dunstable Downs, a steep section of the Chiltern scarp. Near Wendover is Coombe Hill, 260 m (853 ft) above sea level. The more gently sloping country – the dip slope – to the southeast of the Chiltern scarp is also generally referred to as part of the Chilterns; it contains much beech woodland and many villages.
Landscape and land use 
Enclosed fields account for almost 66% of the "Area of Outstanding Natural Beauty" (AONB) area. The next most important, and archetypal, landscape form is woodland, covering 21% of the Chilterns, which is thus one of the most heavily wooded areas in England. Built-up areas (settlements and industry) make up over 5% of the land area; parks and gardens nearly 4%, open land (commons, heaths and downland) is 2%, and the remaining 2% includes a variety of uses, including communications, military, open land, recreation, utilities and water.
The Chilterns are almost entirely located within the Thames drainage basin, and also drain towards several major Thames tributaries, most notably the Lea, which rises in the eastern Chilterns, the Colne to the south, and the Thame to the north and west. Other rivers arising near the Chilterns include the Mimram, Ver, Gade, Bulbourne, Chess, Misbourne and Wye. These are classified as chalk streams, although the Lea is degraded by water from road drains and sewage treatment works. The River Thames flows through a gap between the Berkshire Downs and the Chilterns. Portions of the northern and north-eastern Chilterns around Leighton Buzzard and Hitchin are drained by the Ouzel, Flit and Hiz, all tributaries of the Great Ouse (the last two via the Ivel).
Transport routes 
A number of transport routes pass through the Chilterns in natural or man-made corridors. There are also over 2,000 km (1,200 mi) of public footpaths in the Chilterns, including long-distance trackways such as the Icknield Way and The Ridgeway. The M40 motorway passes through the Chilterns in Buckinghamshire and Oxfordshire sections, with a deep cutting through the Stokenchurch Gap. The M1 motorway crosses the Bedfordshire section near Luton. Other major roads include the A413, the A41 and the A5.
Railways include the Chiltern Main Line via High Wycombe and Princes Risborough, and the London to Aylesbury Line via Amersham. Nearby the West Coast Main Line runs through Berkhamsted and the Midland Main Line with First Capital Connect calls at Luton. The Great Western Main Line and its branches such as the Henley and Marlow branch lines link the southern side of the Chilterns with London Paddington. The Chinnor and Princes Risborough Railway is a preserved line. In 2012 the UK Government announced that the proposed High Speed 2 rail route would pass through the Chilterns near Amersham, partly through tunnels and partly at surface level.
Air corridors from Luton Airport pass over the Chilterns to the east and west of the airport.
There are no navigable rivers (apart from the River Thames), though the Grand Union Canal passes through the Chilterns between Berkhamsted and Marsworth following the course of the Colne, Gade, Bulbourne and (after crossing a watershed) the Ouzel. This canal has branches to Wendover and Aylesbury.
In pre-Roman times, the Chiltern ridge provided a relatively safe and easily navigable route across southern Iron Age England, thus the Icknield Way (one of England's ancient prehistoric trackways) follows the line of the hills. The name "Chiltern" comes from the Cilternsæte, a tribe that occupied the area in the early Anglo-Saxon period.
Until the coming of the railways and, later, the motor-car, the Chilterns were largely rural with country towns situated on the main routes through the hills. The position of the hills, northwest of London, affected the routing of major roads, railways and canals. These were funnelled through convenient valleys (e.g. High Wycombe, Hemel Hempstead) and encouraged settlement and, later, commuter housing. As at 2002 there were 100,000 people living within the AoNB area of the Chilterns.
The western edge of the Chilterns is notable for its ancient strip parishes, elongated parishes with villages in the flatter land below the escarpment and woodland and summer pastures in the higher land.
List of towns and villages in the Chiltern hills area 
- Aldbury, Amersham, Apsley, Ashridge
- Barton-le-Clay, Beaconsfield, Bellingdon, Berkhamsted, Bledlow Ridge, Bovingdon, Bradenham, Breachwood Green, Buckland Common
- Caddington, Chalfont St Giles, Chalfont St Peter, Chartridge, Chesham, Chinnor, Chiltern Green, Christmas Common, Cholesbury, Coleshill
- Dunsmore, Dunstable
- Edlesborough, Ellesborough
- Fawley, Fingest, Flackwell Heath, Frieth
- Gerrards Cross, Goring-On-Thames, Great Kingshill, Great Missenden, Great Hampden, Great Offley
- Halton, Hambleden, Hawridge, Hazlemere, Hemel Hempstead, Henley-on-Thames, Hexton, High Wycombe, Hitchin, Hughenden
- Lane End, Latimer Ley Hill, Little Chalfont, Little Kingshill, Little Missenden, Little Gaddesden, Lilley, Luton
- Markyate, Marlow, Marlow Bottom, Medmenham
- Naphill, Nettlebed, Nuffield, Oxfordshire
- Penn, Pishill, Princes Risborough, Prestwood, Redbourn
- Skirmett, Sharpenhoe, Shiplake, Southend, Speen, St Leonards, Stokenchurch, Stonor, Streatley (Beds), Studham
- Thame, The Lee, Tring, Turville, Tylers Green
- Walter's Ash, Watlington, Wendover, West Wycombe, Whitwell, Whipsnade, Wigginton, Woodcote
Strip parishes partly in the Chilterns 
- Bedfordshire: Eaton Bray, Toddington, Totternhoe
- Buckinghamshire: Aston Clinton, Bledlow, Buckland, Drayton Beauchamp, Great Kimble, Horsenden, The Lee, Marsworth, Monks Risborough, Pitstone, Princes Risborough, Saunderton, Stoke Mandeville, Weston Turville
- Hertfordshire: Tring, Wigginton
- Oxfordshire: Aston Rowant, Checkendon, Chinnor, Ipsden, Lewknor, Mongewell, Newnham Murren, Nuffield, Pyrton, Shirburn, South Stoke, Watlington
The hills have been exploited for their natural resources for millennia. The chalk has been quarried for the manufacture of cement, and flint for local building material. Beechwoods supplied furniture makers with quality hardwood. The area was once (and still is to a lesser degree) renowned for its chair-making industry, centred on the towns of Chesham and High Wycombe (the nickname of Wycombe Wanderers Football Club is the Chairboys). The clean water from the aquifer is still used for public supply and the rivers and streams have fed watercress beds. The chalk of the hills is an important aquifer, exploited to provide water supplies in the area; it has been suggested that over-exploitation has led to the disappearance of some streams.
In a region short of building stone, local clay deposits and timber provided the raw materials for brick manufacture. Where available, flint was also used for construction; it is still used in modern buildings, although restricted to decoration to give a vernacular appearance.
Mediaeval strip parishes reflected the diversity of land from clay farmland, through wooded slopes to downland. Their boundaries were often drawn to include a section of each type of land, resulting in an irregular county boundary between, say, Bedfordshire and Hertfordshire. These have tended to be smoothed out by successive reorganisations.
In modern times, as people have come to appreciate open country, the area has become a visitor destination and the National Trust has acquired land to preserve its character, for example at Ashridge, near Tring. In places, with the reduction of sheep grazing, action has been taken to maintain open downland by suppressing the natural growth of scrub and birch woodland. In the 1920s and 1930s, the Youth Hostels Association established several youth hostels for people visiting the hills.
The Chilterns is an Area of Outstanding Natural Beauty (AONB) and so enjoys special protection from major developments, which should not take place in such areas except in exceptional circumstances. This protection applies to major development proposals that raise issues of national significance. In 2000 the government confirmed that the landscape qualities of AONBs are equivalent to those of National Parks, and that the protection given to both types of area by the land use planning system should also be equivalent.
Chilterns Conservation Board 
The Chilterns Conservation Board was established by Parliamentary Order in July 2004. It is an independent body comprising 27 members drawn from the relevant local authorities and from those living in local communities within the Chiltern AONB area.
The Board’s purposes are set out in Countryside and Rights of Way Act 2000: In summary these are:- First, to conserve and enhance the natural beauty of the AONB, and increase the understanding and enjoyment by the public of the special qualities of the AONB. Second, while taking account of the first purpose, to foster the economic and social wellbeing of local communities within the AONB. Third, to publish and promote the implementation of a management plan for the AONB.
In contrast to National Parks, the Chilterns - as other AONBs - do not possess their own planning authority. The Board has an advisory role on planning and development matters and seeks to influence the actions of local government by commenting upon planning applications.
The local authorities (four County Councils, one Unitary Authority and ten District and Borough Councils) are expected to respect the area's status as a designated Area of Outstanding Natural Beauty.
High Speed Rail 2 
In October 2010 the government confirmed proposals for the High Speed 2 rail link from London to Birmingham with a recommended route through the Chilterns AONB. The Conservation Board has made clear it is opposed to the routing of HS2 through the Chilterns AONB.
Chiltern Hundreds 
The Chilterns includes the Chiltern Hundreds. By established custom, Members of the British Parliament, who are prohibited from resigning their seats directly, may apply for the Stewardship of the Chiltern Hundreds as a device to enable their departure from the House (see Resignation from the House of Commons).
The Chilterns in popular culture 
The opening credits of the BBC sitcom The Vicar of Dibley feature an aerial shot of the Stokenchurch Gap. Travelling north this is a major excavation which takes the M40 motorway down from the Chilterns into Oxfordshire. It is between junctions 5 (Stokenchurch) and 6 (Thame and Watlington). The chalk that forms the hills can clearly be seen on both sides of the cutting when driving on the motorway.
See also 
- The Changing Landscape of the Chilterns Chilterns AoNB, Accessed 19 February 2012
- L. W. Hepple and A. M. Doggett, The Chilterns, 2nd ed, Phillimore, 1994, ISBN 0-85033-833-6, page 7.
- Chiltern Society, The Chilterns
- Rawson, P.F. 2006. Cretaceous: sea levels peak as the North Atlantic opens. In: P.J. Brenchley and P.F. Rawson (Eds) The Geology of England and Wales, p.365-393. The Geological Society ISBN 978-1-86239-200-7
- Anderson, R., P.H. Bridges, M.R. Leeder and B.W. Sellwood (Eds) 1979. A Dynamic Stratigraphy of the British Isles: A Study in Crustal Evolution. p. 241. George Allen and Unwin, London. ISBN 0-412-44510-7
- Natural England
- B.S. Nau, C. R. Boon, and J. P. Knowles, Bedfordshire Wildlife, Castlemead, 1987, ISBN 0-948555-05-X, page 71.
- DidYouKnow.pdf Chilterns AoNB, Accessed 19 February 2012
- Chilerns AoNB website - HS2, Accessed 20 February 2012
- Hepple, Leslie; Doggett, Alison (1971). The Chilterns. England: Phillimore & Co Ltd. ISBN 0-85033-833-6.
- Planning Policy Statement 7: Sustainable Development in Rural Areas
- Chiltern Conservation Board - Our Role, Accessed 10 December 2012
- Chilterns Conservation Board
- Chilterns Conservation Board - statement objecting to HS2, Accessed 12 December 2012