Note: this article is a work in progress.
Long ago the caldera of Mount Shushroar got invaded by seawater, cooling down miles of its throat and most of the dikes. The steady flow of water, getting vaporized by the heat, left a thick crust of salt everywhere, stabilizing the tunnels.
There are only a few active dikes left on the south side of the volcano, while the others are accessible by foot. Animals and creatures of the the region seem to avoid this area.
Salt Crust by Tillerz
Mount Shushroar (Wild Lands), day 1 - While exploring the steaming flanks of Mount Shushroar, we accidentally found a huge system of caves underneath, by falling into a hole that was hidden in the shadows of some rocks. We are calling it "The Downbelow". Be aware that all the volcanic rocks are quite sharp and you can totally rip your precious clothing if you brush along them.
The Downbelow is a vast system of tunnels and caverns connected to the central cave below the caldera of Mount Shushroar, which stretches down several miles where it finally hits the ground of rocks and magma pools. If you wanted to reach the bottom by foot, you would have to use the tunnels, sometimes having to climb down to a lower level.
Descending down, the temperate rises from a chilly frost at the top of the mountain to sweaty heat at the bottom, with rock-melting heat when you come close to the magma pool. There are a few locations, where seawater seeps through the rock, only to hit the magma and getting vaporized immediately. Somewhere between all the walls, vents and pools stands a large gate, engulfed in flames.
Fauna & Flora
The mix of magma, salt and Aeum has created unique specimens only available in this area.
Living Flame by Pixabay/Tillerz
Living Flame Living flames are self-aware balls of fire, that are fed by a greater source nearby. They have no apparent goal except defending themselves or the source that nourishes them.
Googma Between the rocks and magma pools at the bottom of the Downbelow, a strange material pokes out. It has been named Googma by Geertruud Smallbottom, who has discovered it first. It feels warm and rubbery to the touch, and it reacts to pressure.
Great Balls of Fire
Geertruud Smallbottom, The Underbelly of the Wild Lands
The Downbelow (Wild Lands), day 12 - Googma: do not touch it! It becomes a surface with a thousand protruding hands and fights back, and not in a way you will like! Probably.
These balls of rock and magma float above smaller vents and seem to keep the magma flow under control. They are about 2 foot in diameter.
Saltberries Saltberries are small droplets of magma, coated by salt and Aeum, which keeps their heat sealed inside until released from their shell. If the coat is broken, the droplet is released, its heat radiating into the environment and it is then slowly cooling off. Practical use: One berry is enough to light a fire or make water in a small cauldron boil (you just break the berry and drop it in, later fishing it out of the water).
Fetch me some snacks - Saltberries might be something that people pay heaps of money for, with benign or malicious intend. Hello from the other side - Something is calling, and it is coming from the Downbelow, behind that fiery gate.
Underground / Subterranean
dike: side arm
magma: molten rock
throat: main channel