The original idea [for Destroy All Monsters!] was to show all of the monsters. We then started thinking about undersea farming. Eventually, we came up with the idea of an island on which all of the monsters had been collected for scientific study. You see, we imagined that undersea farming would be required to feed all of the monsters. I very much wanted to explore that idea, but because of financial constraints, I was not allowed to do so. Only the idea of an island of monsters survived.

As quoted by David Milner, "Ishiro Honda Interview", Kaiju Conversations (December 1992)