New tunnel building technique

[LONDONER]

So the greater the weight, the better the stones fit? Then surely adhesive is not necessary. That's good news then.

The video demonstrated that with the machine on top of the newly built tunnel.

I would make a projection about seismic activity on the location though, that could be a problem if it falls within such an area.

The Phoenician arch is within an earthquake area and there was a 6.2 earthquake a few weeks ago but after 3,000 years the arch is still standing,