Many years ago I worked for a company that supplied props to production companies. One wanted a sandcastle for a beach commercial but the sandcastle had to be moveable! Well, moving a sandcastle, even if it's on a hard surface, will cause it to fall apart. So I went to the beach, got several buckets of damp sand, came home and mixed the damp sand with plaster of paris and built my sandcastle on a a piece of plywood. Voila! Moveable and the board was easily covered up with sand.
There was another production company who wanted in the middle of winter, and another one who wanted me to get pigeons to stay on the back of a park bench without flying away, but those stories will be for another time.
When I lived in San Francisco some years ago, there were sand artist that built many beautiful sculptures on the beach. They amazed me then and this one is right up there with the great ones. Amazing puzzle.
There was another production company who wanted in the middle of winter, and another one who wanted me to get pigeons to stay on the back of a park bench without flying away, but those stories will be for another time.