It started with a writing prompt--"You and your family go to the beach.  Your dad digs a hole to make a sandcastle an his spade hits something hard.  It's a. . . "

A few leading questions later, "What did the treasure chest look like?"  "Then what happened?"  "Was the cave rocky or sandy?" and a lost civilization was born.

Last night instead of playing video games, watching TV or whatever it is that other children do in the evenings, my boyswere making up their own underground lost civilization. Complete with maps. We had  to make them go to bed with the promise that they could work on thier civilization in the morning.

So far there is a desalinization plant that distributes water as rain and pieces of the sun captured in past space exploration and providing genuine sunlight so that the citizens won't suffer from vitamin D deficiency. Yep, we're nerds here.