Yan Fei had a strong sense of crisis. Although he had acquired the Drone Avatar and Artificial Whale, as well as many defense weapons, he still felt insecure. Therefore, whether it was the Super Nuclear Power Station serving as the energy core or Yang Qi's laboratory serving as the cornerstone for technological advancement, or any other important structures and departments, he had them built far beneath the surface. The structures above ground were mere decoys, meant to conceal the targets below.
Below Dream Island was solid rock, becoming ever more so the deeper one went. At a depth of one hundred meters, the hardness of the rocks became unfathomably strong. At this point, the underground targets were virtually indestructible by external forces, unless sabotaged from within. This was the primary reason Yan Fei chose to build critical infrastructures underground.
