@Zoofan15 I wrote to the director of the Melbourne zoo long before the current and now former exhibit was built about the then size of the elephant yard/exhibit, he replied that they were in fact enlarging the then yard to a larger size but I don't know how small the exhibit was before that!
Melbourne’s elephant house (and presumably the exhibit) were built in 1944, so I imagine it was very cramped prior to the extension. Auckland Zoo had an elephant house and small adjoining yard; and Wellington Zoo merely had an elephant house, so Melbourne’s original set up was probably somewhere between that and Taronga’s antiquated (but comparatively large) exhibit in size (with Taronga’s also extended in the 1980’s).
Auckland’s elephant were walked across to elephant pool once a day and enjoyed walks around the zoo (as did Wellington’s), so that compensated for such cramped confident to a degree - though exhibits like Melbourne’s (2003-2025) and Auckland’s (1992-2024) were a welcome progression; and Werribee and Monarto’s complexes even more so.