Your title is a bit misleading. It's not one tunnel or an interconnected tunnel network. And most of the tunnels are pretty short. No more than 50 meters most of the time.
I hated that show with a passion when my kid first started watching it. Then one night after he went to bed, he left it on TV and I got stoned and just couldn't be bothered to change it while I played on my phone. Then I got to where I put my phone down and was just legit watching it and laughing my ass off. After that, I found myself sitting there watching it with him and enjoying it totally sober.