Game Boy built a dam in the stream at the house we were staying while we were waiting/unpacking/etc. The dam made a pretty big pool of water, and it ran faster after he did it. He also spent a lot of time clearing weeds from the stream back, too.
Then, we had a lot of boxes. We believe in reduce/reuse/recycle. A lot of the boxes went to a parishioner whose son is moving. The really big ones we let Game Boy have. This is his first construction.
He has a roof and doors, too.
Sadly, the wind blew it over. I think that there will be a new construction later.