Level 108 Epic(x4) ^^^
A statue in middle of nowhere.
Occasionally a group of Dracurion stoneweavers will spawn around it and after a while animate it, and then it will very slowly walk towards Ganak's Battlement.
Along the road to the Battlement are 21 ballistas that must be repaired by crafting and then fired at the statue to knock it down, then it can be damaged for 60 seconds. Each ballista can only be fired once.
If it actually reaches Ganak's Battlement you will still have a small window of time to damage it.