Many of the authors whose books I have read give some clues as to what ley lines are, but none has yet defined the term precisely. To Alfred Watkins, who did some of the earliest ley research along the crumbling ruins of England, they were little more than ancient trackways along which men travelled to trade goods across the country. To Peter Heselton and others, they are lines of energy. Some believe they are like the veins of the earth, pulsing energy along specific tracks and especially where two lines meet in a crossroads. Along these lines, oftentimes special structures are built. In some cases the lines may be caused by the activities within and travels between certain places.
In his Elements of Earth Mysteries, Heselton outlines some of the types of structures which may indicate the presence of a ley line. Here are a few:
Map of Sonoma County.
I would add to this list:
Ley lines probably run through the Badlands in South Dakota, where rock formations like these are common. The Badlands are so named for the Lakota legends which told of evil spirits that dwelled in the rocky hills.
Heselton describes a theory from Brian Larkman that concludes the existance of "virtual particles" which exist mainly on the nonmaterial plane, but which sometimes will momentarily leap into the physical plane, just into view. He felt it was a kind of "psychic spectrum" which some people can see more of than others. Those who are sensitive to these energies will be more able to locate leys. but others may find the use of a pendulum or dowsing rod useful in locating ley lines.