I have been leveling a paladin as protection from level 10 to 70, and this was one of the best spots i found.
I found it when i went to do some quests in nagrand. At the Sunspring Post, which is a "village" west of Halaa, there is mobs called Murkblood Brute - NPC - World of Warcraft , Murkblood Scavenger - NPC - World of Warcraft and Murkblood Raider - NPC - World of Warcraft . They are packed very close to each other, don't do any spells and hit faster then most mobs 64+. I leveled here from 64-69, which went on about 1 week in 8 hours / day playing. I hope this will help people, it surely helped me level at prot.