The idea was developed in early 20th-century Europe, with ley line believers arguing that these alignments were recognised by ancient societies that deliberately erected structures along them.
They also argued that in prehistory, as in the present, it was impractical to travel in a straight line across hilly or mountainous areas of Britain, rendering his leys unlikely as trade routes.
Belief in ley lines nevertheless remains common among some esoteric religious groups, such as forms of modern Paganism, in both Europe and North America.
Archaeologists note that there is no evidence that ley lines were a recognised phenomenon among ancient European societies and that attempts to draw them typically rely on linking together structures that were built in different historical periods.
Skeptics have also stressed that the esoteric idea of earth energies running through ley lines has not been scientifically verified, remaining an article of faith for its believers.
[3] The idea of "leys" as paths traversing the British landscape was developed by Alfred Watkins, a wealthy businessman and antiquarian who lived in Hereford.
[8] Watkins had drawn upon earlier research; he cited the work of the English astronomer Norman Lockyer, who had argued that ancient alignments might be oriented to sunrise and sunset at solstices.
[13] His critics noted that the straight lines he proposed would have been highly impractical means of crossing hilly or mountainous terrain, and that many of the sites he selected as evidence for the leys were of disparate historical origins.
Crawford filed these letters under a section of his archive titled "Crankeries" and was annoyed that educated people believed such ideas when they were demonstrably incorrect.
[19] The historian Ronald Hutton similarly noted that there had been a "virtual demise" in the idea by the 1950s, in part due to "a natural weariness with a spent enthusiasm".
[13] It was in the latter decade of this period that a belief in ley lines was taken up by members of the counterculture,[13] where—in the words of the archaeologist Matthew Johnson—they were attributed with "sacred significance or mystical power".
[19] In his 1961 book Skyways and Landmarks, Tony Wedd published his idea that Watkins' leys were both real and served as ancient markers to guide alien spacecraft that were visiting Earth.
[21] He came to this conclusion after comparing Watkins' ideas with those of the French ufologist Aimé Michel, who argued for the existence of "orthotenies", lines along which alien spacecraft travelled.
[25][better source needed] He proposed that an advanced ancient society that had once covered much of the world had established ley lines across the landscape to harness this lung mei energy.
[23] In the mid-1970s Michell then published a detailed case study of the West Penwith district of Cornwall, laying out what he believed to be the ley lines in the area.
[30] He presented this as a challenge to archaeologists, urging them to examine his ideas in detail and stating that he would donate a large sum of money to charity if they could disprove them.
[22] It was later edited by Paul Screeton, who also wrote the book Quicksilver Heritage, in which he argued that the Neolithic period had seen an idyllic society devoted to spirituality but that this was brought to an end through the introduction of metal technologies in the Bronze Age.
[36] Ley hunters nevertheless often took an interest in the work of archaeo-astronomers like Alexander Thom and Euan Mackie, being attracted to their arguments about the existence of sophisticated astronomer-priests in British prehistory.
[30] In suggesting that prehistoric Britons were far more advanced in mathematics and astronomy than archaeologists had previously accepted, Thom's work was seen as giving additional credibility to the beliefs of ley hunters.
[39] Thom lent the idea of leys some support; in 1971 he stated the view that Neolithic British engineers would have been capable of surveying a straight line between two points that were otherwise not visible from each other.
He was more concerned than many other ley hunters with finding objective evidence for the idea that unusual forms of energy could be measured at places where prehistoric communities had erected structures.
[36] He was one of the founding members of the Dragon Project, launched in London in 1977 with the purpose of conducting radioactivity and ultrasonic tests at prehistoric sites, particularly the stone circles created in the Late Neolithic and Early Bronze Age.
[36] The Dragon Project continued its research throughout the 1980s, finding that certain prehistoric sites did show higher or lower than average rates of radiation but that others did not and that there was no consistent pattern.
[41] From one perspective, the tale of ley-hunting is one of a classic modern religious movement, arising with an apocalyptic language which appropriated some of the tropes of evangelical Christianity, flourished for a brief time, and then subsided into a set of motifs and assumptions retained by a particular subculture of believers.
The neglect of landscape and sensory experience by mainstream archaeology in the mid twentieth century was indeed a serious omission, which earth mysteries researchers could well have remedied to the lasting benefit of knowledge [...] Misled by a fixed and dogmatic set of ideas, however, they passed this by to focus on an attempted proof of beliefs which were ultimately based on faith alone.
[46] A prominent example of this was the work of Christopher Tilley, who devised the idea of phenomenology, or using human senses to experience a landscape as a means of trying to ascertain how past societies would have done the same.
[47] He also noted that the ley hunting community had "functioned as an indispensable training ground for a small but important group of non-academic scholars who have made a genuine contribution to the study of folklore and mythology.
[51] Research that took place in 2014 for instance found that various modern Druids and other Pagans believed that there were ley lines focusing on the Early Neolithic site of Coldrum Long Barrow in Kent, southeast England.
A study by David George Kendall used the techniques of shape analysis to examine the triangles formed by standing stones to deduce if these were often arranged in straight lines.
[19] In 2004, John Bruno Hare wrote: Watkins never attributed any supernatural significance to leys; he believed that they were simply pathways that had been used for trade or ceremonial purposes, very ancient in origin, possibly dating back to the Neolithic, certainly pre-Roman.