Ley Lines

Eire has active "Ley" lines (described by Alfred Watkins in "The Old Straight Track", 1922). The GURPS book "Places of Mystery" presented some of the "Ley" spells below. I treat Ley lines as being areas (1 hex wide) of High Mana (pB147, or pM6) with intersections being Very High mana. They are also typically aspected, usually to the Plant or an Elemental college, but not always. Often a Ley line will also give you a bonus to your skill level in the aspected college. Some (many) ley lines are unstable; they don't move, but fade in and out.
Ley College
Sense Ley Information

Ley Communication Regular
("Places of Mystery" has more spells, but they are not readily available in Eire.)
Ley Travel Regular
Lets you walk along a Ley line without incurring fatigue as you normally would from a days march. You travel as if you are on a modern freeway: straight and flat (see Long Distance travel). You are also unaffected by the weather (rain, heat, etc) regarding distance travelled per day. The spell must be re-cast when you start down another Ley line.