Small park? I would certainly not classify it as so. I have visited Nordens Ark twice, once in 1996 and once in 2004. It is a faboulous park featuring, as Kiang so rightly stated, mostly endangered animals from northern climes and mountainous areas of the world. Almost all of the animals are from Europe and Asia with a few South Americans (maned wolves, parrots and chilean southern pudus).
The visitor pathway through the park is either dirt paths or wooden walkways layed aorund a small mountain and the journey around it takes several hours if you also take your time to look at the animals. It is also located next to a fjord to which there is a lookout and the view is stunning.
The animals have some absolutely stunning enclosures in geniuine Swedish woodland or on actual mountain slopes. No amount of mock rock can even hope to create the effect seen here. Some of the key species here are red panda, european wildcat, amur cat, amur leopard, amur tiger, snow leopard, wolverine european otter, european lynx, european grey wolf, himalaya tahr and przewalskii wild horse.
All of these species have fantastic exhibits and the one for snow leopards is the best I have seen anywhere! It is essentially a huge fenced-in mountain side with pine trees and several natural rock terraces. In this exhibit, as indeed it is in all of the park, the animals can be a pain to find and sometimes you won't see them at all. The wolverines also have the best exhibit I have seen anywhere. It is a thick pine forrest with a few clearings of grass. Visitors cannot overlook the whole exhibit so it is a good idea to show up at feeding time!
Another quite interesting aspect to Nordens Ark is actually their farmyard. I mostly pass by these "petting zoos" during my zoo-visits but this one must not be missed! The focus here is endangered domestic breeds, such as the telemark cattle from Norway. The farm itself is large and very modern and goes a long way to educate people (especially children) where the meat, milk and eggs they eat every day actually comes from.
All in all Nordens Ark is a grand experience and a truly inspiring park.