Ley lines are special track ways that run throughout the land, said to have spiritual significance. Points at which ley lines converge are magical hot spots and where portals are located. Bremin is located at one of these convergences, in both the original and alternate universes.
History
During Viv Lau's investigation of her brother Andy's involvement with magic being tied to his disappearance, she came across the concept of ley lines and researched them.
After locating several Ley lines on a map, she showed her findings to Detective Roland, who passed it off.