You may have seen (much cuter versions of) these on Pinterest or other places. But here is ours. A table fort. I used old bags that sheets came in for the windows, sample fabrics that a store was getting rid of for most of the top and sides (thus the patchy look) and some bias tape. It might not win the cutest table fort award, but I'm pretty sure the kids don't care. I love that this fort folds up nice and small and is easy to store, but is so easy to set up again. It's nice to have something quick to pull out on a day that we're home and the kids want something new to do.
The thing that made this fort a success were the pockets that I sewed onto the inside of the walls. The kids love having a place to put their books and small toys.