well the pools are not really a feature the zoos want to adveritse. i mean, arcitectually, very unappealing to a visitor, unlike the clock or ele house. The original giraffe house is also heritage, but i dont ebelive it has a H. The map, remember, is just a thing for genral visitors. It does not advertise everything, such as all heritage things, the vet block, even offices will not be advetrised.