Skansen Akvarium was founded as an aquarium/terrarium inside Skansen in Stockholm. However, it has now developed into a tropical zoo with many exhibits featuring animals from the rainforest or savannah, as well as an aquarium part. The zoo has a large number of small mammals, particularly monkeys and lemurs.
Why not? To be honest, the name is a bit misleading.
The Skansen-Aquarium is much more than an aquarium. Except their reptiles, amphibians and fishes they keep several mammals (mostly primates). For exampel; sevaral tamarin and marmoset species, lemurs, two-toed sloths and the meerkats.
Edit: Sorry Toddy. Seems like you were faster than me