The Chiltern Hills are chalk hills in southern England. They go 70 mi (115 km) southwest to northeast through parts of Oxfordshire, Buckinghamshire, Hertfordshire, and Bedfordshire. This makes a well-marked escarpment to the northwest and a gentle southeast slope to the River Thames.
Considerable areas are now under the National Trust and are popular tourist attractions. The greatest elevation is Coombe Hill (852 ft [260 m]) near Wendover. The dense beechwoods still cover the western portions. They were once the basis of the traditional furniture industry of High Wycombe. Several passes through the Chiltern Hills are used by roads and railways to London.