Concept art for the third section of the first level.
The first level is a cave system called the depths, the third section is called starlight.
Wanderers gave it this name because small glow worms nest and dwell on the ceiling of the cave, giving the cave the illusion of stars in the darkness.
Starlight is the darkest part of The Depths, but it is also the only one that connects the cave to the outside world.
Here we see an entrance to the cave, otherwise it would be pitch black.