Digging up my old LEGOs

Hi ya all. I just dug out my old LEGOs, dirty and clearly very loved! I'm probably posting more of the findings once I've dug through all of them. The very first two objects that caught my eye (well, they were at the top of the pile so...) are these two raised base plates. Two things I'm now wondering/asking: What would you do with these? As in is there some cool MOCs that utilities these bases or is there something very specific you would like to build on them (I very probably have the...