The Chiltern Hills are a chalk escarpment in southern England, northwest of London, covering 660 square miles (1,700 km2) across Oxfordshire, Buckinghamshire, Hertfordshire, and Bedfordshire, stretching 45 miles (72 km) from Goring-on-Thames in the southwest to Hitchin in the northeast. The hills are 12 miles (19 km) at their widest.
Near Nettlebed, Oxfordshire
Chalk visible in ploughed soil at the foot of the Chiltern Hill escarpment near Shirburn on the Buckinghamshire/Oxfordshire border
Viewed from The Ridgeway: eastern trailhead on Ivinghoe Beacon
Stokenchurch Gap, a cutting built to carry the M40 motorway through a section of the Chiltern Hills
An escarpment is a steep slope or long cliff that forms as a result of faulting or erosion and separates two relatively level areas having different elevations.
Shaded and colored image from the Shuttle Radar Topography Mission—shows an elevation model of New Zealand's Alpine Fault running about 500 km (300 mi) long. The escarpment is flanked by a chain of hills squeezed between the fault and the mountains of New Zealand's Southern Alps. Northeast is towards the top.
The Sierra Escarpment in California