Brewmaster monk spot in the Jade Temple. Constant respawn of "water fiend" Water Fiend - NPC - World of Warcraft which gives just over 9k xp per kill at L87.
You can pull the whole room with keg smash and stand on the edge of the circle and aoe it down. By the time they are dead, the whole room has respawned, so other players won't be pissed at you.
They drop tons of greens, and vial of moving water which vendor for a reasonable amount. Dont try to do this unless you are tank and reasonably geared, or just pull less of the room, 2 mages and a hunter died trying to emulate me
31% into 87 took me 1hr 35mins to ding 88.
You'll probably need to be on the quest chain "the Serpent's heart" to access the temple in this way, I think the entrance is closed (except to enter the instance itself unless you are at this stage in the quest).
Pic of location attached.