This is an excellent thread, and one that I was just thinking of creating myself! I was thinking about the Clore Building in London zoo, home to a vast majority of those listings on Zootierliste which seem too good to be true and when you click on them, disappoint you with zero current holders. Then again, go farther back in history and you also have big rarities like Thylacine at london zoo, that would be a tough choice!