I had bought a small bag of river pebbles to use in the riverbank piece and after I had used them I still had ¾ bag left and it was leaking . I have enough things in my shed to trip me or turn my ankle so I thought the best solution would be to make it into a piece and this form suggested itself. It also allowed me to use a lot of my offcuts of mesh and although not perfect it does do the job. I do like the contrast of colours and textures .