Interesting! I’ve been idly wanting to do this, as well as somehow obtaining/building a ground penetrating radar setup to check for the presence of caves/tunnels.

My location has prohibition tunnels not far from my property, where I have been inside one section which was used for IT equipment at a business.

I’m already trenching some holes due to recent rain flooding and now I want to get even further into it with this wiki entry being posted. Thanks!