Not too original perhaps but like many I would love to go back in time to the 1800s and see all the extinct and or no longer exhibited species in London Zoo, Bronx Zoo and others.
I want to go back to the time the Toronto Zoo opened in 1974 til the mid 1990s. The list is extensive. African Elephants, Tasmanian Devils, Chinese Leopards, African Painted Dogs, Dholes (phased out now), coyotes, Wallaroo, Eastern Quoll, Grey-headed Flying Fruit Bat, Eastern Genet, European Genet, Liberian Mongoose, Pronghorn, South African Fur Seal, Musk Ox, Bongo, and a slew of others.
Toronto Zoo - Former Toronto Zoo Animals
Also want to go back to the opening of African Lion Safari in 1969 til early to mid 1990s. They had African Elephants (I think they had them and Asians at the same time) in the drive through reserve, African Wild Dogs, Bengal Tiger (I'm not sure how purebred they were; they had white ones in the 1990s; I *think* they left sometime as late the 2010s), Sealions (not sure about the species; they were part of the boat ride around the island that now houses a few primate species), Chimpanzees (lived on the island) and Striped Hyenas.