Intrigues of the Dark Elves (WAR History and Lore)  

On the Destruction side of the map, interact with an Emptied Coffer located at 25.8k/13.5k at the base of a lone tree standing on a broken hill. You may have to use some creative jumping to make it over the cracks in the earth to get to the coffer.

History & Lore in The Shadowlands