I was stuck on this myself, and have saw a few people asking around.
Darnassus - Beside the Darnassus Flight Path (Guessing)
Gilneas - Beside the Darnassus Flight Path
Stormwind - Beside the Stormwind Flight Path
Ironforge - Beside the Ironforge Flight Path
Gnomeregan - Beside the Ironforge Flight Path
Exodar - Beside the Exodar Flight Path (Guessing)
I know it's quite obvious, but i was stuck on the Gnomeregan and Gilneas ones, so that's all it's really for.