We walked the tunnel 3 or 4 times. The first just to get a feel, then we attempted to live stream but only made it about 100m into the tunnel before we lost mobile data (Seba had the GoPro on his head during the live stream, I might post his video). We returned to street level and set up the GoPro for this video. Shot 4K at 30 frames per minute and edited with CapCut.