Hiya
Some will remember "Corp'rethar: The Horror Gate" in Icecrown where you could park your RaF boosted toon ontop of it and go to AoE the mobs below. In full heirlooms and with RaFl linked account you could potentially level to lvl 80 pretty fast compared to normal play.
Well since the introduction of CRZ this place as its wellknown has become pretty camped and getting exclusive access to the mobs isn't easy as a booster anymore.
However, there is another place in Icecrown that is less known (until now I guess) that serves to the same end. Since I finished yesterday levelling my toon to lvl 80 using mostly this place (due to Corp'rethar being full) I thought should share it. I did a search and couldn't find any reference to the mobs atleast, and since I saw zero other boosters in CRZ (just some cloth farmers) I belive it can be worth sharing
The Mobs you are going after is the Mjordin Combatant close to Shadow Vault (view link for exact location, it's wowdb, don't worry). They are lvl 79 and 80 so they can reward a tad bit less XP then the mobs in Corp, but they have an 100% uptime. It seems they are programmed to have atleast 3 mobs up at any time so anytime you kill them all they instantly respawn. They are a part of a questchaing (and a daily) so I guess it by that reason they behave in that way.
There are several places you can park your lvl 1-80 boosted toon, but on the small cliffs just beside the path with the patrolling "hunter" is where I found it to be best. Not to close to the path as they will aggo when lowlevels but just go a step up from first plateau and your golden. There you will in range from a Guild XP banner if you put it middelish of the arena of Combatants.
Otherwise just follow the first guide. Put on full heirlooms (on boosted toon), keep banners up, and boredom level I used a lvl 85 shadowpriest to farm with just instant dots and occational mind spikes (when mana was low). And since they have a 100% uptime you will never get to rest. Since the NPCs are 79-80 you cannot be higher then lvl 85 with the toon that does the killing, otherwise the XP will dwindle, maybe a lvl 83-84 will be even better.
A nice thing is since they are programmed to always be "up", even if there is several here doing this there will always be mobs up.
Make sure you leave some up if anyone comes and does the quests.
When I compared Corp'rethar and this place I found them to be roughly the same mins per level. A little less XP from Mjordin but no downtime to compensate.
For anyone who feels the urge to reply "Noob, just level the normal way", "Dungeon boosting ftw" or likewise demeaning but non contributing posts, please note that we are all diffrent, some like to level like this, some dont Its all good, be happy!