I found this spot today while wondering Dustwallow Marsh.
Theses mobs have basically a instant respawn timer. By the time I got done with the second pull, the first pull would be respawned.
The location is Lost Point . I dont have the loc #'s atm, my cartographer seems to be out of order.
Watch out for the tree's though, There seems to be a glitch with Blizzard to try and cast on the tree's behind you if you don't aim the Blizzard Circle Perfect.
Happy Leveling
P.S
You dont getting dismounted when riding onto the tower.