Underground Fort?

I don't even know the best way to explain these photos especially since I don't even understand what they're doing but here goes. My husband promised to built the kids a fort but his definition of fort I guess is a little different from most (although his definition of a lot of things is different than most). The kids, along with Grant, have been digging a big hole in the back corner of our yard and are excited that it will eventually be an underground hideout or fort. Tonight Grant put this old satellite dish on top for a roof and the kids were so excited to get in. The hole is still pretty small so they got in with their buckets and shovels and started to try and dig there way out. There seems to be something wrong with this whole concept on so many levels but the kids and Grant were having a blast so who am I to ruin the fun. Grant says that he's going to put walls and a floor in once it's all dug out. I think I'll just continue to shake my head and smile for the sake of the kids.
Here they are with their flash lights under the roof digging away.

There is a little hole in the "satellite roof" so here's two pictures from up above looking down.