How about an underwater city?
Is that not more feasible?
You know, like the one in bioshock?
That's a crazy idea.
One small underground earthquake and we are all dead.
I'll pass on that one.
Do have experienced on any earthquake yet? It depends how you build your underground city.
I've been in at least 3 small earthquakes, but never a bigger one.
If the underground city lasts over 10 years, I will probably drop in to visit.
