Originally (before swimming pools), this referred to a slot opening that would allow water to drain off a roof or a ship’s deck. Around the swimming pool, a scupper looks much the same, except the water is draining into the swimming pool itself. A scupper can be a simple opening, or it can be highly decorative, such as with a lion’s face or other ornate styling.

Also see Water Wok for an especially popular, stylized form of scupper.