Bury the ancient High Keep coin within the Blessed Knoll ( 418, 35, 719 ) Copy/waypoint 418, 35, 719.
Click the sparkling pile of dirt in the middle of the druid ring. When you do, an NPC called Glade Guardian appears, throws you up in the air and says that "Lord Kithicor's rest is supposed to be eternal."
Recover the buried coin
Click the glowing green pile of dirt to reveal a dagger. Then click the dagger to pick it up.