Not including bad exhibits at zoos, but nothing makes me more frustrated with a zoo than incorrect, or non-specific labeling. Then it shows the guests that they are learning something that isn't entirely true. Almost every zoo that has a black or white rhino, does this. I have a list of incorrect signage at the Cincinnati Zoo, with a little help from someone else. The first word will be the Sign and the second will be the actual species.
Wildlife Canyon
-(this one doesn't bother me)Sumatran rhinoceros to Western Sumatran Rhinoceros
-Takin to Sichuan takin
Reptile House
-Beaded lizard to Mexican beaded lizard
-Gila monster to Reticulated Gila monster
-Rainbow boa to Brazilian rainbow boa
Night Hunters
-Vampire bat to Common vampire bat
-Giant fruit bat to Indian flying fox
-Ocelot to Southern Brazilian ocelot and Texas ocelot
-Sand cat to Arabian sand cat
-Siberian lynx to Eastern Siberian lynx
Gorilla World
-Colobus monkey to Eastern black-and-white colobus
-Crowned guenon to Grey's crowned guenon or Crested Mona monkey
World of the Insect
-Emerald beetle to Emerald ash borer
Manatee Springs
-Land hermit crab to Caribbean hermit crab
-Mosquitofish to Western mosquitofish
Siegfried and Roy's White Lions of Timbavati
-White Lion to Southeast African lion
Rhino Reserve
-Bongo to Eastern bongo
-Black rhinoceros to Eastern black rhinoceros
Jungle Trails
-Mueller's Gibbon to Muell'er Bornean or grey gibbon
-Slender-tailed cloud rat to Northern Luzon giant cloud rat
-Yellow-billed hornbill to Eastern yellow-billed hornbill
Wings of the World
-Kookaburra to Laughing Kookaburra
Children's Zoo
-Three-banded armadillo to Southern three-banded armadillo
Elephant Reserve
-Asian Elephant to Indian Elephant
Discovery Forest
-Two-toed sloth to Linnaeus's two-toed sloth
Wetland Trails
-Sandhill crane to Florida Sandhill crane
Please add more.
Wildlife Canyon
-(this one doesn't bother me)Sumatran rhinoceros to Western Sumatran Rhinoceros
-Takin to Sichuan takin
Reptile House
-Beaded lizard to Mexican beaded lizard
-Gila monster to Reticulated Gila monster
-Rainbow boa to Brazilian rainbow boa
Night Hunters
-Vampire bat to Common vampire bat
-Giant fruit bat to Indian flying fox
-Ocelot to Southern Brazilian ocelot and Texas ocelot
-Sand cat to Arabian sand cat
-Siberian lynx to Eastern Siberian lynx
Gorilla World
-Colobus monkey to Eastern black-and-white colobus
-Crowned guenon to Grey's crowned guenon or Crested Mona monkey
World of the Insect
-Emerald beetle to Emerald ash borer
Manatee Springs
-Land hermit crab to Caribbean hermit crab
-Mosquitofish to Western mosquitofish
Siegfried and Roy's White Lions of Timbavati
-White Lion to Southeast African lion
Rhino Reserve
-Bongo to Eastern bongo
-Black rhinoceros to Eastern black rhinoceros
Jungle Trails
-Mueller's Gibbon to Muell'er Bornean or grey gibbon
-Slender-tailed cloud rat to Northern Luzon giant cloud rat
-Yellow-billed hornbill to Eastern yellow-billed hornbill
Wings of the World
-Kookaburra to Laughing Kookaburra
Children's Zoo
-Three-banded armadillo to Southern three-banded armadillo
Elephant Reserve
-Asian Elephant to Indian Elephant
Discovery Forest
-Two-toed sloth to Linnaeus's two-toed sloth
Wetland Trails
-Sandhill crane to Florida Sandhill crane
Please add more.