Tunnels

Written by Cyborg Starfish

Sometimes staying in the dark is safer.

Geography

Aven Armand by WikimediaImages from Pixabay

'Tunnels' with a capital 'T' refers to multipe expansive and interlocking cave systems spread across the entire planet, in an enormous web that links every above ground area together. It has been used as a way to travel between locations where travelling above ground would be too hazardous, and it has always been a place for different Elphin cultures across the world to meet and exchange meaning.

Many rivers flow through the Tunnels, and there are even underground lakes and seas located deep within the earth. Tunnel sizes can range from small corridors to enormous halls, from tiny rooms to massive dripstone caves. Many Tunnels are treacherous, walls and ceilings can be unstable, or the floor can be riddled with deep holes barely visible to the eye.

A Light in the Darkness

Many of the Tunnels are dimly lit by luminous crystals or bioluminescent creatures, in any colour imagineable. Walking through the Tunnels may feel as walking directly through a night sky, as the walls, ceilings and floors are covered with tiny lights. Even in the tiniest corridor, one may find a beautiful display of light and colour. Other corridors and halls are lit by razor-sharp beams.

Ecosystem

Air coming in from the surface as well as the presence of underground forests generate a more or less steady oxygen flow in many Tunnels, but certainly not all of them. The air density varies very much from Tunnel to Tunnel, and so does the area's ability to host life. The underground forests are found near bodies of water that house large swarms of micro-organisms that produce a gas that chemically replicates the energy that would normally come from sunlight, allowing underground forests to grow and prosper without needing actual sunlight. The flora are connected in an inticrate web of symbiotic relations, as plants and trees are capable of growing into one another and creating new forms.

Ecosystem Cycles

The underground forests are not only famous for their ability to thrive in less than desireable circumstances, but also of the rapid changes the undergo each cycle. During the height of each cycle, which is a fairly short period, plants and trees rapidly mutate, grow into one another or apart from one another, creating all kinds of different species that both support and feed off one another. After the height of the cycle is over the forest calms down and falls into a half-slumber, producing oxygen at a lesser rate (although many algae and micro-organisms continue to produce oxygen at the same rate as before), causing the activities of nearby creatures to slow down a bit. This half-slumber lasts for about 75 days, after which the forest wakes up again and becomes more active over the course of the Cycle, then once again escalating in a feast of mutations and cross-pollinations.

Fauna & Flora

The Tunnels are home to a biome that exists nowhere above ground. Large underground forests can be found in bigger caves, and many luminous mosses, algae, fungi and even flowers glow on the walls and ceilings. There are also Tunnels that are completely barren, however, as the forest needs proximity to freshwater in order to survive. Smaller plants may also grow near saltwater, and the underground seas are full of seaweed that exists nowhere else on the planet.
The trees found in the Tunnels are mostly evergreens. The largest types can become big enough to host a cave system of their own, with roots and branches taking the form of massive bridges and arches. Luminous veins adorn their trunks, and if one looks closely, they can see the water flowing through these veins. Strange underground palm-like trees or fungal trees can be found closer to the surface, where underground temperatures are slightly higher.

Creatures of the Tunnels

Insects, coral-like creatures, small critters, bat-like creatures, bird-like creatures and reptiles prowl the forests. They usually don't get much larger than the average height of an Elphin, with a few exceptions, such as worm-moles. Most of these animals are also bioluminescent in some way, and most animals use their bioluminescence as a way to either lure prey or ward off predators.

by alexlamp from Pixabay

Communication often goes through ultrasound, and many species use echolocation in order to get around. The underground waters do host fish from the waters above, since many of the cave systems are connected to the sea or to lakes or rivers. Most of the creatures in the underground seas are also the creatures who live at the bottom of the surface sea. Some aquatic creatures are unique to the tunnels however. Just like other creatures, they are more likely to be bioluminescent, and almost all of them are omnivores. In fact, the vast majority of all animals in the Tunnels are omnivores, which tremendously increases their chances of survival in the Tunnels. In addition, animals need to watch out for flesh-eating plants. Though most of these plants are too small to catch a fully-grown Elphin, Elphin children are still a welcome meal for these plants, and some symbiotic plants can work together to catch bigger prey. The same goes for small creatures that hunt in groups or operate as a hive-mind.
All of this being said, the creatures of the Tunnels are, as a rule, less hostile to Elphin than many of the creatures in the overworld. That doesn't mean that the Tunnels are completely free from pollution, radiation or destructive metaphysical forces. These things might be more rare underground, but when they occur they are usually much more destructive than they would be above ground, due to the lack of space in the Tunnels.

Finding Ways to Breathe

A challenge that is exclusive to the Tunnels is the fact that the forested areas are the only source of oxygen in areas that do not have direct link to the surface. This is why settlement are always located near the forests and why travelling routes only go through tunnels that are directly linked to a forested area or to the surface. Some Elphin communities use tools to more or less measure the amount of oxygen in a specific Tunnel.

Natural Resources

by Avisuals Official from Pixabay

Wood from the medium-sized trees in the forest is known to be unusually flexible and sturdy, and as such this wood has been the go-to resource for archers to make their bows of. This wood is also used in the building of underground settlements, some of these settlements may be built inside the trunks of the giant trees. The availability of metal and gems is heavily dependent on the location. Since the Tunnels span the entire planet, not all resources will be found everywhere, and the biome takes on slightly different forms depending on the location. Many an ore deposit is linked to the Tunnels somehow, which makes it easier for Elphin to build mines. The luminous crystals are often used as light sources above ground. Many mosses, flowers and fungi from the Tunnels can be used as medicine or as drugs, and these two are quite overlapping when it comes to these plants. The animals of the underground are ill-suited for domestication, but alliances have been formed between Elphin communities and the communities of another species. Tools and clothing can be made from basically any creature living in the underground, though not all parts of the creatures are useful, and it requires a lot of creativity to make good use of the actually useful materials. Some plants can also be used to make tools and clothing, aside from wood, of course.
The most important take-away is that the availability of resources in the Tunnels is heavily dependent on the place from which the Tunnels are accessed. If one is particularly unfortunate, one might just stumble upon a barren tunnel with no resources whatsoever, and they will have to travel a bit deeper to find something of use.

Type

Underground / Subterranean

Inhabiting Species

• Shkttt

Related Materials

• Heat Crystals

Related Historical Events

• 95
  Founding of Enthanaes