Fungal Depths

Very WIP

A vast, fungal-infested cave network underneath the continent of Arjin, stretching for countless leagues throughout the dark caverns. Most of the fungal depths is one giant, interconnected network of tunnels, caves and giant geodes, allowing one to travel for unfathomable distances underground. Not all of the fungal systems are connected, of course, but enough of them are to form something akin to an underground world.

The Kykr have barely even begun exploring this unknown world, hidden beneath the surface of their very own civilisation.

"It's like traveling through another world entirely. The light is eerie. It comes mostly from the ground and walls, not from above. It has a creepy vibe to it. The air smells nothing like you've ever experienced. It's thick, heavy and strongly fragrant. Even sounds behave differently down there. It's a terrifying, and wondrous, experience traveling the Fungal Depths.

— Renowned Explorer
Alternative Name(s)
The Deep Dark
Underground / Subterranean
Location under


The geography of such a vast world is difficult to describe. The major features shift both with depth and region, but it seems to follow a pattern, especially when it comes to depth. The Kykr have made great efforts to document these layers.

The Shining Tunnels

The Shining Tunnels are the first layer of the Fungal Depths. A network of narrow, winding tunnels, intersecting with small caves here and there. These tunnels are populated by small, fist-sized, ovate-shaped mushrooms that glow faintly in the dark.

The color of the glow shifts with depth and region, but so far, orange, yellow, blue, green and red mushrooms have been found, with occasional clusters of purple mushrooms.

Polyp Plains

Fungal Cavern

Deeper beneath the Shining Tunnels lie the Polyp Plains. Large, open caverns covered in huge, low-stemmed amanitas. The wide caps of these amanitas form the basis for other, smaller mushrooms to grow upon them. The Polyp Plains are absolutely covered in small to medium-sized mushrooms of all shapes and sizes, but the giant amanita of course dominate the view.

The ceiling of these monstrous caverns are packed with stalactites, some stretching as long as entire ships. These voids are lit by faint bioluminescense, produced by some of the fungi here. But it is murky and moist, for the most part. During the time of sporing, the air here can become difficult to breathe.

Musky Marshes

The Musky Marshes lie beyond and beneath the Polyp Plains. It's even more wet and muggy than the plains and feature several undergound streams and rivers, varying in size from just a few steps across, to far enough you couldn't even throw a rock to the other side.

The Marshes are large tunnels, winding through the underground, reminiscent of the Shining Tunnels, but far, far larger. Even in the brightest areas you cannot see the ceiling of these tunnels and they are large enough to comfortably fit river-boats on the larger rivers.

The Marshes feature forests of ovate shaped mushroom-trees and vast, slithering stems of a mushroomy substance. They look more like roots of trees than mushrooms but are unmistakenly of mushroomy material. These winding "mushroom vines" creep in and out of the terrain, and some have mushroom trees growing on them, indicating they are very old.

The Fungal Depths

Fungal Cavern

Beneath the Marshes, the Fungal Depths begin proper. While it is a word to describe the entire underground, this realm is what truly gave the place its name. The Fungal Depths, also called the Fungal Forest, is a marvellous space, dominated by gigantic mushtrees of all shapes and colors.

In difference from the other realms, with the exception of the Shining Tunnels, the Fungal Depths are filled with bioluminescent fungi. Almost all the large mushtrees have at least some bioluminescense, making the Depths a surprisingly bright and "welcoming" space, although the eerie glow given off by the mushtrees is somewhat unsettling.

The smaller mushrooms tend to not shine at all, or at least not as bright, with the exception of some of the smaller ovates, similar to the ones in the Shining Tunnels. Most of the light come either from the giant mushtrees, or from tight clusters of thin-stemmed ovates.


It is not known from where the fungi of the depths get their energy and nutrients. Generally, fungus feeds of off other plant- and animal life, but the fungal depths are so full of fungi and little other vegetation that this seems unlikely. There is ample animal life in the caverns. Mostly slow-moving grazers who feed on the mushrooms, but there are also a number of large predators that seem to operate in cycles similar to bears on the surface, with periods of low-intensity or even hibernation, in spite of the temperatures at this depth barely shifting at all with the seasons above.

Localized Phenomena

Natural resources


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