Dadlamassu, that board is epic. I've been thinking about some sort of cave structure. I'm not sure what sort of scale to make it. Something to ponder I guess.
The cave was made largely by our grandson (aged 7 at the time). It is in sections the base, the middle two sections fit together with a ledge inside and the lid. We had to adjust the lid so that Kong can stand inside. We have two different tops - the skull for when it is on Skull Island and, under construction, a rocky/volcanic one for when it is the base for an evil mastermind ready to take over the world with his devilish schemes. We might even make a new base level with underground chambers for him. It would then also serve as a centrepieces for a Lord of the Rings/Hobbit game - etc etc
Got to be multi-purpose as it is very big!