The Caverns of Living Steel are a location somewhere on Azeroth or Draenor. The [Mark of the Khor] is given out to robo-farmers who have harvested at least 1,000 trees there.
This article or section includes speculation, observations or opinions possibly supported by lore or by Blizzard officials. It should not be taken as representing official lore.
It is possible that the [Living Steel] originated from these caverns.