This is the opening to underground networks which could contain Labs, Chemical Weaponary, a prison complex etc. the possibilities are endless.
So I started by PVA gluing a lot of sand to it and then spraying Chaos Black.
. . . Short but sweet. It took me a long time to do it!! I'm in Hobby turmoil at the moment. Finding it hard to keep my eyes on one project at a time!
Next; I paint the bastard.