Hi I have a 3m x 3m tiled courtyard /balcony with a drain and a tap that I want to landscape suitable for my dog to use when needed. I am thinking of a Japanese style theme, so with a suitable edge where the balustrade is, perhaps topping with pea gravel or perhaps astro turf on a suitable substrate could work? The doorway has a threshold that allows a bit of scope for extra height. What would you suggest? Thanks Jack