Note: This is part of the setting of the world that our Steampunk personas come from, which is also content for the game we are working on.
Down below the floating rocks, there is a thick mist of water and Aether vapors. Anyone who has traveled into mists has not come back. Sometimes, the mists move, but only a glimpse of smaller chunks of land can be spied from a distance. These “rockbergs” are hidden within the mists and can easily sink any Airship that can’t see them. This is the primary reason no one ever tries to go beyond the mists. There is mystery and wonder within the mists that hold up the rocks. Are there remnants of Hollow Earth down there? Is there life or another civilization down there? Perhaps more inhabitable rocks, or mining rocks? Perhaps there is an ocean, or just a big bubble of Aether at the center of the earth, or perhaps nothing at all. Curiosity is there, but so is the danger.