Artis is small, at least in comparison to the zoos I know. Situated in the middle of a city block, there was nowhere in the park that I can remember not seeing the three-story buildings surrounding it.
One thing that struck me was how many of the large exhibits were so unnatural-looking. The monkeys and goats are on concrete islands with little that would make me believe the animals were in their natural habitats. As someone who believes somewhat in animal rights (I'm no PETA person though, ;)), I felt bad for these animals.
When I went (May, 2003), many of the buildings were undergoing renovations. The elephant house for instance was closed, so I didn't get to see everything.
This may sound like a negative review, but there was a number of fun and cool stuff here as well. Artis seemed to have a nice "collection" of penguins and kangaroos, and there is a grand old building which houses the aquarium and natural-history-style museum. There are skeletons and skulls in this section, as well as some child artwork and a small section with panoramas. The aquarium is small, but one part I thought was really interesting was a mock-canal, made out to look like one of the regular Amsterdam canals. The water itself is cleaner although there is the occasional license plate thrown in for the fish to swim around.
Artis considers itself to have five focal points within its gates, the zoo and aquarium are a couple of them, as are geological studies (which I didn't experience while there), a planetarium and a botanical garden. With that latter part in mind, there is a nice little Japanese rock garden right near the aquarium.
The planetarium is right near the entrance to the park. The shows are free, but they are in Dutch. I didn't inquire about translations, as I wanted to practice my Dutch a little. Around the planetarium theater are astronomical displays, many of which are hands-on.
Artis as a stand-alone event may leave a bit to be desired. The size of the park and the exhibits make this one of the more dull zoos I have been to. But it is a nice time, especially on a nice day. What I found to be a good day was doing the zoo and the Dutch Resistance Museum in the span of an afternoon. These two sites are not even a block apart from one another, and both are small but interesting in their own ways. For those who might get overwhelmed by the Nazi aspects of the Resistance Museum, Artis should be a good way to relax afterwards.