The owners of this pen say that they really like the lobed-shape of their pool because the ducks can swim in their own areas. Based on their other photos, I don' think they have a drain, so they have to lift the whole thing out when they need to clean it.
Mint & Lime Juice Cubes - You need to do this. Muddle up some fresh lime pulp & juice, pour into an ice cube tray, add a mint leaf & freeze. Pop a few into a glass of ice tea or soda or a cocktail for a lovely little kiss of lime & mint.