Agaia

Agaia is a world outside of Arborea. It's separated from Arborea by barrier called The Veil.

Agaia was result of Manahan's actions. He grew curious of things beyond the borders of Arborea and tried to break through to outside. This caused havoc across the lands. Titans Shara and Arun wake due this and repaired the damage. And Manahan was banished to Agaia he had unintentionally created.

In early TERA development it was intended to use Agaia as place for cross-server PvP.