Ley lines () are straight alignments drawn between various historic structures, prehistoric sites and prominent landmarks. 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. Since the 1960s, members of the Earth Mysteries movement and other esoteric traditions have commonly believed that such ley lines demarcate "earth energies" and serve as guides for alien spacecraft. Archaeologists and scientists regard ley lines as an example of pseudoarchaeology and pseudoscience. The idea of "leys" as straight tracks across the landscape was put forward by the English antiquarian Alfred Watkins in the 1920s, particularly in his book The Old Straight Track. He argued that straight lines could be drawn between various historic structures and that these represented trade routes created by ancient British societies. Although he gained a small following, Watkins' ideas were never accepted by the British archaeological...