The Advent Woods are a dungeon in Deliverance.
It leads to the Lost Ruins.
The Advent Woods are where the player, Kerah, and Quillon first land on Proteus. They navigate the forest and enter an odd temple. Inside, Quillon has doubts about the significance of the ruins, but they proceed further inside anyways.
After the events in the Lost Ruins, it's still possible to enter the Advent Woods, though the part containing the Lost Ruins are blocked by boulders and become inaccessible.