If you saw my Sandland video, you know about the sandstone tunnels we’re digging! Sandstone is a great material, being relatively easy to dig and yet structurally sound enough to last for hundreds of years with no artificial supports. (Some examples of local sandstone caves and tunnels can be found here, here, and here).
I’ll be doing a larger project in these tunnels that involves carving out an underground room, so stay tuned for that sometime next year!