exotarium seems to be a relatively common word in European collections now -- does it stem from Frankfurt Zoo's buildling, or was it an existing word before the Zoo used it?
To my everlasting disappointment, the one time I visited Frankfurt Zoo (in 2004) I didn't go into the Exotarium because I didn't have enough money on me for the extra entrance fee
@Chlidonias: I don't know the answer to your first question, sorry.
But I wonder about your second phrase. Frankfurt Zoo has indeed had an extra fee for the Exotarium. But IF(!) I remember correctly, this is gone more then 8 years ago (it is now included in the ordinary entrance fee). Are you sure about the time?