Sorry to be so long getting back, and thanks for the "Welcome Home" MadridMan (not that I've been anywhere!)
Jo-Anne's explanation in spot on, and ley lines do seem to be a British study subject, although they are said to exist everywhere.
The reason this arose was as a result of the number of foreigners who live here (in Nerja, Málaga) and who say they felt an urge or pull to be here. Many "blamed" this on the strength of the ley lines in the area, and I was commissioned by a local magazine (
www.nerjaessential.com) to write a piece on it. But finding out much about the phenomenon has been, well, not easy!
Thanks for your responses. If I get anywhere, I'll post the info here.
¡Un saludo de España!