Xiang Shan saw bright light again after a long time.
This is an artificial underground pool, with nearly a hundred square meters of space filled with air above.
"The water pressure here is comparable to the Shallow Sea," Freeman introduced, "Although after modifications, dolphins can adapt to such depths, they are essentially creatures of the Shallow Sea. It'll be much more comfortable with illumination."
Xiang Shan looked around: "Wow, this is quite impressive. How did you come up with the idea to dig such a large place underwater?"
"This wasn't originally dug for habitation, but as a mine." Freeman shook his head, "It was only after sixty years of mining that we thought of doing this. At that time, many dolphins' psychological issues were getting worse, so I modified the mine a bit."
As he spoke, he pointed to the robot returning from a dark cave below: "The cave's scale is still expanding."
