The 139km (87-mile) Ridgeway National Trail starts at Overton Hill, near Avebury, Wiltshire, and finishes at Ivinghoe Beacon, Buckinghamshire. Typically taking 5-7 days to walk, it follows a ridge of chalk hills across southern England, passing through two Areas of Outstanding Natural Beauty: the chalky North Wessex Downs and the more wooded environs of the Chiltern Hills. It is well waymarked, follows good tracks and paths and, by not exceeding 300m, is fairly low-level throughout. The guide gives information on historic sites and details of excursions to nearby towns and villages, as well as practical information on useful contacts and accommodation. Primarily written as a west-to-east route and illustrated with OS map extracts, the guide also gives details of the trail in reverse. The trail follows tracks that have been walked for over 5000 years, making it probably the oldest road in Britain. Along its length early man has left some remarkable features from the UNESCO World Heritage site of Avebury and the Uffington White Horse, to Iron Age hill forts and earthworks.