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.

Akershus Castle and Fortress is a medieval complex that was built to protect Oslo. It has also been used as a prison. The main building is now used for official events and dinners for the foreign heads of state. Akershus fortress is still a military area but is open to the public daily until 21:00. In addition to the castle, the Norwegian Armed Forces Museum and Norway's Resistance Museum can be visited there. Norwegian Royalty has been buried in the Royal Mausoleum in the castle. His Majesty the Kings Guard is responsible for guarding the fortress, with stationary guard posts during open hours, and patrols at night time. One of the stationary postings at the entrance is a popular photography spot for tourists visiting the fortress.

Frogner Park is a public park, historically a part of Frogner Manor. The manor house is located in the south of the park and is home to Oslo City Museum. Frogner Park contains, in its present centre, the well-known Gustav Vigeland installation of 212 bronze and granite sculptures. The Monolith Plateau is a platform in the north of Frogner Park made of steps that houses the Monolith totem itself. 36 figure groups reside on the elevation, representing a “circle of life” theme. 

Holmenkollbakken is a large ski jumping hill located at Holmenkollen. It's a large hill with the capacity for 70,000 spectators, requiring the special permit for athletes to use. Holmenkollen has hosted the Holmenkollen Ski Festival since 1892. It's also a cross-country and biathlon venue. Holmenkollbakken is co-located with the Holmenkollen Ski Museum, which presents the history of skiing. It has a simulator that allows the public to visualize a ski jump in the hill.

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.

Oslo Cathedral is an ancient church, dating to the 17th century. The Norwegian Royal Family and the Norwegian Government use the Cathedral for public events. In 2001, Oslo Cathedral was the site of the wedding of Haakon, Crown Prince of Norway, and Mette-Marit Tjessem Høiby. 

Oslo fjord is not a fjord in the geological sense - in Norwegian, the term fjord can refer to a wide range of waterways. It is an inlet in the south-east of Norway, stretching from an imaginary line between the Torbjørnskjær and Færder lighthouses and down to Langesund in the south to Oslo in the north. In the summer there are boats of all sizes on the fjord, and it is possible to go kayaking, canoeing, fishing, and sailing.

Opera house is a beautiful white structure, located by the water in Oslo harbor. It is the home of The Norwegian National Opera and Ballet, and the national opera theatre. The roof of the building angles to ground level, creating a large plaza that invites pedestrians to walk up and enjoy the panoramic views of Oslo. 

The Royal Palace was constructed for the new French-born king of unified Norway and Sweden. It has been the official royal residence since then. The palace is open for visitors with the advance appointment late June to mid-August. The beautiful baroque park of the palace is open for visitors every day.

The Viking Ship Museum is part of the Museum of Cultural History of the University of Oslo and houses archaeological finds from different areas of Scandinavia. The main attractions are the Oseberg ship, Gokstad ship, and Tune ship. Additionally, the Viking Age display includes sleds, beds, a horse cart, wood carving, tent components, buckets, and other grave goods.