The walk-through Bird House at Basel Zoo comprises free flying bird species besides several caged individuals (such as guira cuckoo and Swainson's Toucan). The small integrated aviaries along the walls are not too bad either, but the enormous tropical house and its vegetation is like a little jungle where you can sit and wait for some of the most beautiful bird species to appear at feeding spots or little ponds. The building style of the Bird House reveals that the inside once comprised rows of aviaries and not free-flying birds as it does today. In fact, since the 1950s the numerous traditional aviaries have been gradually removed and the bird species added to the walk-through exhibit. Several of the larger bird species, such as the kookaburra, have access to an outdoor aviary as well.