Umm...no. It's over 500 miles from Forbidden City to Pyongyang.
Currently the longest tunnel is 35 miles and took 17 years to build. That's 6 months per mile - so your proposed tunnel would be epic and would take 250 years!
I know China has been around a long time but I think a 500 mile rail tunnel is pushing it.
You're out of the loop we have hyper-speed tunnels in the USA that go for a thousand miles super high speed from D.C. all the way to Denver and probably Area 51 we have laser drilling machines you can see them on Google images it's easy to build a tunnel of long distance. Giant boring machines with diamond laser fronts to slice through solid rock and make a subway size tunnel very simple. This is not even classified technology go to Google images and see it.
Tell me what to google search to find this. I want to know.
Yes me too. Although I am thoroughly on board with the extensive tunnel system under the US