This is the second moonbase module I've designed, by my current standards it seems very amateur, but not too bad. (The first failed to comply to the no-build boundaries, and by protocol was infested with fleebnorks and launched into space.) The tanks are for water and air (I guess), and it's connected by a simple airlock and corner corridor.
I've never built a real module, which is a shame, but I don't even own a gray baseplate. I made it physically buildable nonetheless.
The dome removed, with assorted trees and flowers.
Inside the base. Notice spray bottles, support pillars, air filters, and dirty shovel.
The stairwell leading down to the airlock. Alas, non-working doors.