Also, you may have to try several times. Even young children can enjoy it. Once successful, complications are minimal. Birds seldom get too close. One needs lots of room.
Rain soaks in very fast.
Too many people doing the same thing can also cause problems. If there are no complications, it can be very peaceful. A rock will serve as an anchor. If things break loose from it, however, you will not get a second chance. Bransford, John D. and Marcia K. Johnson.