06-15-2016, 03:42 AM
If they could do it...why can't we?
Anyone up to the challenge?
If the structures didn't cave-in through the millenia -- that would be astounding.
How long would it take to 'build' one of these underground cities?
Constant year-round temperatures. No air conditioning or heating needed. Just the ventilation system to keep fresh air/oxygen flowing through. They might even have access to their own subsurface water supplies...
Anyone up to the challenge?
If the structures didn't cave-in through the millenia -- that would be astounding.
How long would it take to 'build' one of these underground cities?
Constant year-round temperatures. No air conditioning or heating needed. Just the ventilation system to keep fresh air/oxygen flowing through. They might even have access to their own subsurface water supplies...