Water Chasms

The chasms are most known for the water that flows through them, collected from miles around by the bowl-shaped nature of the midnight expanse. For the wet season, the whole chasm can flood until its ecosystem is entirely underwater, while gradually draining away during the dry season until the majority is reduced to a river at the very bottom, or an underground ocean at the center.

With the extremes of the water chasms, the wildlife had to adapt to be both fully aquatic and fully terrestrial, as well as survive on little direct sunlight. Indeed, the sun only shines down to the bottom for mere moments in the highest point of noon, and any other hour is eclipsed by the shadow of the chasm.
  Plantlife clings tightly to the rocks, to keep from being washed away in the annual floods. Some species open up fully only for the time of sunlight, then close and hide against the shadows, roots creating wide networks to choke nutrients out of their neighbors. Carnivorous plants are exceptionally common, and grow large enough to easily take humanoids or large animals as prey.
  The most common creatures in the chasm are demons, taking advantage of the near constant shadows, and large arthropods and arachnids. Arachnids are most active during the dry season, and hide away in cave systems to hibernate through the rainy season floods. The arthropods, on the other hand, are less active during the dry season, only moving to find tender plants, or smaller creatures, to eat. When the rains start, these creatures will mate and lay eggs on the leaves of the largest plants and fungi. When the floods start, these eggs are washed away, to scatter and mature elsewhere. While the floods persist, the arthropods show themselves to be very adept swimmers, easily moving through the waters to find food and mates.

Due to the risks within, travel into the canyons is reserved for extreme need. Teams of water traders will hire mercenaries or paladins to accompany them into the dark chasms to collect water. During droughts, this is the only ready source and water can sell for a lot of money or supplies, making it worth the risks associated with the darkness.