At the end of the Nordnes Peninsula, this aquarium makes a worthwhile trip, especially for families. There are around 60 individual aquaria here, housing lots of interesting marine species from octopi to reef fish, although kids are bound to gravitate to the shark tunnel or the seals and penguins. There's also a tropical zone housing snakes, crocodiles and other reptiles.
On foot, you can get there from Torget in 20 minutes; alternatively, take the Vågen ferry or bus 11.