To have some plants in the pond, I wanted to put some earth. But the problem is with the step, there are a lot of chance that it slips/fall down to the deep.
So, the goal was to make a cuve.
So I built a wall that will allow to contains the earth for the plants. Those "short" plants will be mostly located on the same side, but I will put 1 or 2 other kind of plants in a pot, directly in the pond.