Maybe try getting some metal fence posts and sinking them way into the ground (on the outside next to the cinder blocks) so he cant just push them over?????? Looks nice if you could keep him from pushing them over.
:Well, these can go back to Home Depot as he did what I pretty :much expected - walked straight through them and toppled :and shoved the whole thing away. All righty then. Alas the :joy of large tortoises. (large?, he's still medium). I think :we're going to try just straight 2X12 boards like he has on :the inside border of his pen.