Probably the translator gets casino, a mod for what tunnel,
(to be able to lower a mountain to pass the road and then cover again with earth)
Greare a real and prpria gallery
Not sure if its something you want to take up but if you made the walls like this, for the roof you could do a texture like rock roof, and like this you could terraform around the landscape to create a ''tunnel'' out of it, maybe even have bushes built into the placeavle (if possible) to blend in more... either way i love this mod and as simple as it is ive been neding it for MONTHS