Ultra-Fast XP Grinding 90-100, Draenor (Patreon)

In Frostfire Ridge Draenor there is a cave located between Magnarok, Cracking Plains and Colossal's Fall. This cave was much discussed in Warlords Of Draenor so it is not exactly secret, but for some reason it has not been discussed at all in Legion in any online media. 

The cave was well known for providing great xp. It is full of goren eggs and you simply run over these and baby goren spawn with low health, you simply have to tap them to get xp and they die after 5-10 seconds.  The opportunity was nerfed during wod. 

Fast forward to Legion and the baby goren now award the same XP as any other standard mob at that level. There seems to have been some kind of reset in 7.3.5. The mobs are the only mobs I'm aware of in the game which offer full xp and can effectively be one-shot by a player at the same level.

The difficulty with the cave is that the patrolling elites and other larger goren mobs in the cave are quite difficult to survive. Excellent survivability was required which meant good gear. This is still the case, but I found a good workaround exploit for classes which can port (ie monk, warlock, arcane mage, void elf (racial))

Run into the cave and die. You'll then be sent to the graveyard and put on a spirit flying mount, which can fly indoors. Fly into the cave and onto the point of the top of the spiky blue crystal here : https://youtu.be/I0xHGJg_vlI?t=294

(If you are wondering why I'm linking to Umren's video instead of posting a screenshot it is because of legal issues concerning me using Blizzard art assets outside of youtube).

Resurrect on top of the point of the crystal (this is a bit fiddly, not you are in the right position when your spirit makes a landing sound and stops descending) and put down your port. If you then get into trouble you can port back to the top of the crystal and out of range of melee attacks. You do not cause mobs to evade when you do this.

I would strongly recommend logging in periodically on an high-level alt and clearing out the mobs in the cave-the elite in particular is very difficult to kill for a levelling character in a reasonable timeframe. This should allow your low-level character to kill the low hp mobs easily.