Last year with a training group I used double copes for the first time .On the site there were no animals and the owners were planning to raise the wall in the future. It worked very well and I was pleased to try something new after so many years following the standard system.
During one of the great festivals of stone in Canada . The younger folk there had fun building with butter nut squashes while the rest of us were using rocks. Several members of the Landman family participated in the construction of this Cairn, which turned out to be one of the highlights of the weekend.
This climbing structure was set up in our local park last summer. The children have had great pleasure from going up and down these cast rocks. The surface below is quite spongy so takes any falls without danger. It seems to me that real rocks could be used in this way , the cost would probably be much less. The height is about 2 meters and does require foot holds.