Heorot's Sanctum

It appears in the alternative timeline Reign of Dragons.

History
As the gods let dragons live well into the Divine era, Heorot goes insane and becomes one with them, betraying the Heoboreans. The Heoborean shamans desperately try to bring him back to their senses.

The Traveler arrives at his temple, where Shaman Drageloken debriefs them. He requests to carve a path through the temple's defenses, so that he can infiltrate and reconvince Heorot of his bad thoughts.

On the way to the Temple, several winter creatures and elementals stand guard, including two Spreading Frost guardians. As the ice wall crumbles, Heorot is nowhere to be seen. Instead, an Injured Dragon is encountered that must have been injured from a fight with Heorot.

As the dragon is dealt with, Shaman Drageloken re-appears and reveals his scheme to give birth to a cult of dragons, which shall wipe Eterra clean of weak gods, ushering in a new reign with iron hand. The Traveler cannot get revenge on him however, as he sacrifices himself, bursting in flames.