The Stone Labyrinths are complex tunnels situated all around the cavities of Yliakum's seven levels. Pre-dating even the very existence of the stalactite of Yliakum, the labyrinths were originally all dead ends, until an earthquake changed the tunnel system, forming new routes that led to the surface. This enabled the coming of the non-Kran, non-Lemur races. Some tunnels were also created by Stonehammer dwarves in search of precious ores and crystals. The Stone Labyrinths were where Laanx was self-exiled for many years.
Today, the Stone Labyrinths can be accessed only through the Bronze Doors that guard them. Rumour has it that undiscovered tunnels could lead to worlds similar to Yliakum, and perhaps access to the surface, but no one has ventured far enough into the caves to confirm these theories -- or, at least, no one has returned to do so. Although heavily guarded and largely unexplored, the labyrinths remain one of Yliakum's main sources of food and other resources for the cities. For this reason, many an adventurer might enter the Stone Labyrinths to collect and kill forbidden plants and animals, and often because these might have some magical power.
Fauna and Flora
Inhabitants of Yliakum hunt not only the animals inside these caves for their edible meat and warm furs, but also fungi, moulds, and saprophytes. These plants cannot be found elsewhere, since there are no other suitable environments for them, and their curative and helpful properties are valuable to the people. More pernicious and aggressive creatures also live here. Hunters and gatherers must keep an eye out for these predators, which dominate the less controlled and more dangerous tunnels of the Stone Labyrinths. Legend has it, too, that great stores of wealth are just waiting in these caves for someone clever enough to find and profit from them.
Stone Labyrinth Invasions
Malevolent beasts in the Stone Labyrinths, some possessing terrifying magical powers, break through the fortifications of the Bronze Doors from time to time. These attacks were what necessitated the construction of the Doors in the first place. During times of invasion, The Dome experiences huge waves of migration from villages, towns and cities under attack, and the Octarchy must work together with all Yliakum inhabitants to contain the threat and restore peace.