The
ZooLex Zoo Design Organization is a very good resourse for ideas about high-end exhibits in different zoos worldwide. From my own experience I can highlight the giant aviary in Munich ,
Link.
On the other hand, there exist many small low cost walk-through aviaries (I am unsure what exactly you are looking for), so here are pictures of some such solutions from my country.
South american themed
aviary (full-winged macaws in 5-6 species, amazons, ducks..) in Zlin, quite
simple but well accepted by public.
Asian themed
aviary in the same zoo, for ibises and herons, small but densely planted, even a purple gallinule breeds there.
12 meter high
aviary in Olomouc, it is not a walk-though exhibit but I think it could easily be trasformed into one. The inhabitants are mainly of african origin (secretary bird, ibises, guineafowl, gulls...). I like the clear linies and the simplicity of its architecture, althrough it is an older one (+30years).
Another
aviary in Olomouc, mainly for bigger raptors, with diameter of +70meters.
New walk-through
aviary for water bird species (ibises, herons, gallinule...) in Chomutov, the photo was taken during construction, later it has been more planted and furnitured for visitors.
Walk-through
aviary in Ohrada, for native singing-birds, wery nice planted I think. it is quite
new.
Wery cheap walk-though
aviary for flamingos and other waterfowl also in Ohrada. It has been constructed within few weeks due to the risks of avian influenza 2 years ago.
And at the end one older
aviary for raptors in Prague. It was constructed some 30 years ago as a walk-through exhibit, but many conflicts between birds and visitors caused it has been closed for public shortly after its opening and stayed so till today.