The Depths Below

This network of underground caverns spans the entirety of Daënfel - said to be the hollow corpse of the Titan, whose blood became the seas, back became the mountains and body became the land of this world.
The Maw marks the primary entrance to this dark, endless expanse - the ancient gateway which was sealed by The Avanís Pantheon to keep the endless hordes of creatures that roam this place at bay.
Gorgol is one of the only other documented openings to this place, however there are doubtless many crevices and holes in which one could access this lightless place.