When I was little, my "Bama" made all the grandkids what we all called tepees. They were little tents that easily folded and set up. The awesome thing is that they have lasted a long time. The one above was mine, and now my little guy uses it. He simply loves it!
It is a fairly simple construction of four sides-one with a slit in the middle for a door and the opposite side has a small opening for a window. The four sides are connected with four pockets each holding a one by two piece of wood.