I think we have some great zoo's here in the Netherlands.
Diergaarde Blijdorp in Rotterdam is probably our favorite, just because it is 10 minutes away from my hometown. It's a mixture between a modern zoo and old monumental buildings with lots of nice exhibits for the animals. Also the fact this zoo is constantly evolving and transforming and upgrading it's exhibits it's always fun to return every year.
Other zoo's in the Netherlands are worth the trip as well, especially Ouwehands Dierenpark Rhenen, Burger's Zoo Arnhem and Artis Amsterdam.
We also have a safari park Beekse Bergen, which is worth the trip as well.
But Blijdorp is my favorite.
Edit: Just found a very old picture, probably late 40s. As of today the zoo has been expanded to the left beyond the train tracks.