The Viking Ship Museum is great to combine with the Norwegian Folk Museum as it is only a five minute walk down the street. If you are into the Vikings, definitely check this place out. The main attractions are the Oseberg and Gokstad ships, both pre-dating 1000 AD. The exhibits tell you all about the life of everyday Vikings, the methods they used for ceremonial burials, and displays items such as beds and a horse cart that have been found in archaeological digs. The museum is quite small, as most of the focus is on these extraordinary ships, so it can easily be thrown in to a 24 hour itinerary. Admission is free with the Oslo Pass, otherwise an Adult entry costs NOK 60 (£6, $10).