Sandstone and Sackrete....

[realist]

Depending upon what you want to do will determine how you can use it. Digging holes in the sandstone and then filling them with concrete and rebar will give you anchor points. It can be done on the ground or the walls or for that matter the ceiling. Don't be intimidated with the concrete it is easy to work with. Most people are used to a real wet surrey. Used dryer you can mold and form it to what ever you want. Use a grinder you can polish it and it will make a nice counter top that will rival granite. If you were to used the sandstone to make a kinda plaster or you get a matching color then it would blend in better.

[Kesephist]

My thought was to be using the native rock to close off one of these sandstone caves, using the sackrete as a mortar . Over time, go at one of the interior walls with hammer and chisel and expand the cave from the inside, with care, then taking the resulting minings outside, and making further expansions on the outside.