I only know of two, I think. I'll have to logg onto my toon to find out for sure and i'll update asap.
South Barren Coast (?) has a port. I'f you follow the coast all the way along you'll eventually come across a small rat camp with some tunnels burying underground. I'f you see that camp your in the right area. On a Hill very close to that camp is the guy you have to talk to. Pay him 15k tunar and you'll get your spell.
Cyclop's Fortress (?) is where the other one is. If you know where that is, and you know where to find Grundle you'll find the guy to talk to no problem. Hes on a hill next to the river that leads to grundle in that underwater cave. You'll be able to see the fortress from a distance.