That is to say, there is a terrarium outside of your hexagonal room. Or something like that.
Outside of the glass walls stand tall, lush trees; birds flit among the leaves, and the sound of frogs and crickets fill the air, muffled but cheerful nevertheless. The walls also show cross-sections of the dirt --- in which you see tangled tree roots and even the tiny tunnels of ants --- and also, in one corner, the cross-section of a small, clear pond. Silvery fish glint in the water. Above, the sun shines down, bathing all in its golden light. Everything is quite beautiful ... except for the electrical outlet in one side of the terrarium.
There is a closed door frame (complete with door) here, trailing an electric cord that is plugged into the terrarium.