I've mentioned previously that I plan at least four covers to go over the access hatch over the "far" end on my layout - pallet's I call them - each a removable section to be covered with a different vignette or type of scenery - in order to provide some variety and provide more to "model." The hatch is in the middle of my 'Streets country road and about 40 x 24 inches in extreme dimensions. I had to remove the second pallet I've made (see last two photos) - my 'secret rocket base'- in order to take it to the workshop and begin in earnest to complete the other buildings, missile launchers, and silo door mechanism, etc. I decided to complete a third, simple cover, just a green grass-covered field. Then today, rather than jump into the rocket base project I spent the afternoon arranging this car show. It was fun and my wife and I really like the result.
Those are balloons . . .