The Ridgeway is a ridgeway or ancient trackway described as Britain's oldest road. The section clearly identified as an ancient trackway extends from Wiltshire along the chalk ridge of the Berkshire Downs to the River Thames at the Goring Gap, part of the Icknield Way which ran, not always on the ridge, from Salisbury Plain to East Anglia. The route was adapted and extended as a National Trail, created in 1972. The Ridgeway National Trail follows the ancient Ridgeway from Overton Hill, near Avebury, to Streatley, then follows footpaths and parts of the ancient Icknield Way through the Chiltern Hills to Ivinghoe Beacon in Buckinghamshire. The National Trail is 87 miles (140 km) long.

Ridgeways are a particular type of ancient road that exploits the hard surface of hilltop ridges for use as unpaved, zero-maintenance roads, though they often have the disadvantage of steeper gradients along their courses, and sometimes quite narrow widths. Before the advent of turnpikes or toll roads, ridgeway trails continued to provide the firmest and safest cart tracks. They are generally an opposite to level, valley-bottom, paved roads, which require engineering work to shore up and maintain. Unmaintained valley routes may require greater travelling distances than ridgeways.