It seems like this large metal cage was recently installed inside the children's zoo aviary. I am not sure what the cage was for. All its doors were open, and birds were entering and exiting it at will.
@ZooElephantsMan looks to me like it's a howdy cage. They're fairly common in large mixed-species aviaries, and zoos will place new birds in the howdy cage for a little while before being released to the large aviary in order to acclimate/get used to the other birds. Most aviaries have some version of this, some zoos are just better at hiding/concealing it than others.
