Unlike the eternal darkness, the Underground Cave was never a calm place.
Because most of the regions had only been vaguely surveyed, even the native underground species who had occupied this domain for a long history, didn't own a completely reliable map.
The underground tunnels could stretch for miles; sometimes they expanded into massive caverns more than a thousand meters wide and sometimes they narrowed so even the Cave Dweller couldn't squeeze through. The biggest cavern was like a miniature surface world: there were hills, valleys, an underground river, and lakes. In this three-dimensional environment, most of the species could utilize the cavern ceiling and walls, using their innate ability or a magic spell to fly, hover, or even ride on some of the creatures who could walk on walls (like the giant spiders or some kinds of lizards) and travel freely in this domain.
