An avenue is a more or less parallel sided strip of ground up to about 30m wide with open terminals and side-edges defined by lines of stone or timber uprights and/or a low earthwork comprising a bank and/or outer ditch. Avenues are generally either short (<800m) and straight, or long (>1500m) and sinuous. Often they link stone circles to watercourses, but there are exceptions. All avenues occur within groups of late Neolithic and early Bronze Age ceremonial monuments.
Avenues are recognized as field monuments by their earthworks or from aerial photography by their distinctive parallel side features. In most cases it is the juxtaposition of an avenue with other monuments that provides a clue to authentication. Avenues can be confused with other classes of monuments, especially: cursus, with are distinguished by having earthworks across the terminals and no uprights along the sides; stone alignments which are either single rows of stones or paired stone rows too close together for an avenue; droveways and trackways which link fields and settlements rather than ritual monuments; and pit alignments which have pits rather more closely set than in the edges of avenues.
Specifically excluded from this definition of avenues are single lines of stones leading to, or aligned upon, stone circles and other ritual monuments - these are properly defined as stone alignments - and fenced pathways approaching ceremonial or ritual foci such as timber circles or long barrows - these are components of the monuments they serve and are usually distinguished by their small scale and modest construction.
Avenues have for several centuries been interpreted as ceremonial walkways or processional ways of early Bronze Age date marking the formal route by which ritual monuments were approached.