Chiltern Hills

The Chiltern Hills or the Chilterns are a <a href="/facts/Chalk/b6hepsNS">chalk</a> <a href="/facts/Escarpment/apJ1d2XB">escarpment</a> in <a href="/facts/Southern_England/4amGCPWW">southern England</a>, located to the north-west of London, covering 660 square miles (1,700 km2) across <a href="/facts/Oxfordshire/dc4jQkHB">Oxfordshire</a>, <a href="/facts/Buckinghamshire/WMRE3NJp">Buckinghamshire</a>, <a href="/facts/Hertfordshire/TcBlCoSp">Hertfordshire</a> and <a href="/facts/Bedfordshire/zlyMvSWP">Bedfordshire</a>; they stretch 45 miles (72 km) from <a href="/facts/Goring-on-Thames/nly77cfz">Goring-on-Thames</a> in the south-west to <a href="/facts/Hitchin/qCJad9N3">Hitchin</a> in the north-east. The hills are 12 miles (19 km) at their widest.
In 1964, 833 square kilometers - almost half of the Chiltern Hills - were designated by the <a href="/facts/Countryside_Commission/XbJbJvJw">Countryside Commission</a>
as an <a href="/facts/Area_of_Outstanding_Natural_Beauty/MDTR4U1e">Area of Outstanding Natural Beauty</a> (AONB) under the powers established by the <a href="/facts/National_Parks_and_Access_to_the_Countryside_Act_1949/tRs0eQ4h">National Parks and Access to the Countryside Act 1949</a>.
The north-west boundary of the Chilterns is clearly defined by the <a href="/facts/Escarpment/apJ1d2XB">escarpment</a>. The <a href="/facts/Dip_slope/N2CJTcre">dip slope</a> is by definition more gradual and merges with the landscape to the south-east. The south-west endpoint is the <a href="/facts/River_Thames/XnQWN52L">River Thames</a>. The hills decline slowly in prominence in north-east Bedfordshire.

Chiltern Hills open-in-new

Chiltern Hills