kyekeyf -- it folds over at the top, but it isn't needed, they've never tried to climb it. I have had foster kittens in it that have tried to climb out, as well as a feral cat an squirrels that occasionally get in (and usually, they never even think of climbing it and run along the base in panic). The wire mesh at the bottom is folded over and staked, and at this point, the grass has grown completely through it. This is the fence system -- you have to fix the URL --
http ://pu rrf ectf ence.com/