The collections that
@snowleopard speeds through tend to be the tiny, the arcane, the really fairly unexciting - obscure seaside aquariums, “rescue” centres with a few big cats in rectangular wire mesh cages, centres for local wildlife with a moth-eaten coyote or two. Give him a proper zoo, an Omaha, or a San Diego, or a Wichita, and it takes a little more than a hour to tour.
Certainly the Netherlands contains a number of “whole day” zoos (maybe even
two day zoos); it does also have a number which could be combined on a single day.