"A five-digit district!"
Li Yao was slightly surprised. He knew that he must be well below the sea level from the dull air, but he did not expect that it would be so ridiculously deep.
The habitable planets with a stable tectonic structure that was suitable for mankind generally boasted triple layers, namely the core, the mantle, and the crust. The capital planet of the Imperium was certainly not an exception.
Such habitable planets were like enormous eggs, where the core was the yolk, the mantle was the white, and the crust, which was thirty to fifty kilometers thick, was the thin "eggshell".
While the crust was the thinnest layer, it was the most important area for residence and resource collection for human beings.