In Path of Exile 2 , the “sixth megalith” is part of the Recruit the Ezomytes quest in Stones of Serle: there are 6 Runed Megaliths total , and once you activate all of them, the quest advances to the boss fight.

How to do it

  1. Go to Stones of Serle first.
  1. Activate the Runed Megalith you find near the entrance/checkpoint.
  1. Keep moving around the outer edges of the area to find the rest; the remaining megaliths are also placed near checkpoints.
  1. After all 6 are active, go to the runed area in the middle to spawn Siora, Blade of the Mists.

If it is not working

  • Make sure you have already entered Stones of Serle and not stayed in the Darkness section of Scorched Farmlands.
  • Check whether one of the megaliths is still unlit near a checkpoint on the map edge.
  • If the altar in the middle still does nothing, you likely missed one of the 6 activations.

Quick note

A guide snippet also confirms the objective explicitly says “Activate the remaining Megaliths” after the first one, so the sixth one is not a special hidden step—just the last of the required six.

Would you like the exact quest path from Scorched Farmlands to Holten after the megaliths?