Most roads have a beginning and an end, but the Ridgeway has neither: what is left of it, and it is a emarkable stretch for a road of such antiquity, starts nowhere and concludes in time rather than in space. Since our conventions are finite, and a book by convention must have a beginning and an end, I have adopted for this study that portion of the ancient Ridgeway which the Countryside Commission has marked out as the Ridgeway Path. That begins tidily at Overton Hill, near Avebury, and marches over some forty miles of the most beautiful country in the world to the Thames. The Commission, properly concerned with enabling people to walk freely through as much countryside as possible, carries its path across the Thames to follow the line of the Icknield Way to Ivinghoe Beacon, near Tring. But the Commission's public purposes are wider than mine, and for reasons that I explain in the text my book is chiefly concerned with that part of the Ridgeway that is south and west of the Thames: the stretch, that is, that can still be identified clearly as — that still is — the Ridgeway of antiquity. It must be understood that this is only part of a road, the rest, save for a few odd remnants here and there, having disappeared under the plough and the bitumen of later roadmakers in the last two thousand years of its long history.