Akerselva is a river that flows through Oslo. Akerselva is "Oslo's green lung"; many parks and nature trails are to be found by its path, from Grønland to Maridalsvannet. A walk from along Akerselven from the rural Frysja down through the different parts of Oslo down to the city center is a fantastic experience and a walk through the history of Oslo. Salmon run and spawn in the upper part of the river.

The Kon-Tiki Museum houses vessels and maps from the Kon-Tiki expedition, as well as a library. The museum was initially built to house the Kon-Tiki, a raft of balsa wood of pre-Columbian model that Norwegian adventurer Thor Heyerdahl used to sail from Peru to Polynesia in 1947. Another boat in the museum is the Ra II, a vessel built of reeds according to Heyerdahl's perception of an ancient Egyptian seagoing boat. Heyerdahl sailed the Ra II from North Africa to the Caribbean. The Kon-Tiki Museum is situated near several other museums, including the Fram Museum, the Norwegian Museum of Cultural History; the Viking Ship Museum; and the Norwegian Maritime Museum.