Chiltern Hills AONB

The Chiltern Hills are a chalk escarpment in England northwest of London, covering 660 square miles across Oxfordshire, Buckinghamshire, Hertfordshire, and Bedfordshire, stretching 45 miles from Goring-on-Thames in the southwest to Hitchin in the northeast. The hills are 12 miles at their widest.

In 1965, almost half of the Chiltern Hills was designated as an Area of Outstanding Natural Beauty. The northwest boundary is clearly defined by the escarpment. The dip slope is by definition more gradual, and merges with the landscape to the southeast. The southwest endpoint is the River Thames. The hills decline slowly in prominence in northeast Bedfordshire.