Some claim the tunnels run for 100’s if not 1,000’s of miles in almost all directions. How would your suggestion work, if that’s true?
I think the tunnels will be shorter than some think. The logistics for building a tunnel on that island, with cement and rebar, are demanding to say the least.
There don’t seem to be any stories, from locals, of a huge construction project on the island. How did they construct those tunnels without anyone taking notes? Name of contractor? Drawings?
Do a volumetric analysis. Thousands of miles is unreasonable.
Pump them full of 5% propane 95% oxygen and ignite, the exits will be readily discernable.
People claim a lot of things.
Anyway that’s pretty much what they did on Iwo Jima.