The island boats in the inner harbour. An ordinary Ruter ticket is valid, and most of them run all year.

1.9 HovedøyaOslo's best-known recreation island (0.47 km²), and the one carrying the most history: the ruins of a Cistercian monastery founded in 1147, medieval quarries, fortifications from 1808 with their cannon and powder magazines, and German army barracks from the Second World War. Rich plant life, notable geology, and popular places to swim. Oslo Ferrylive 2.4 BleikøyaA small island in the inner Oslofjord between Hovedøya and Sjursøya, with around 90 holiday cabins from the 1920s and 30s. From 1885 to 1926 it held a sanatorium for children with scrofula, a form of tuberculosis; the writer Oskar Braaten was a patient here as a boy. State-owned and managed by Statsbygg, the government property agency. Oslo Ferrylive 2.5 LindøyaA state-owned island (0.41 km²) in the inner fjord, known for its 289 small cabins organised into 16 sections. The settlement began with tents around 1905. There is a shop, a football pitch and swimming spots open to the public. Oslo Ferrylive 2.6 HerbernGroup of islets southeast of Bygdøy in the inner Oslofjord, made up of Store Herbern and Lille Herbern. Store Herbern is a nature reserve with shore vegetation and several rare species; Lille Herbern is known for its summer restaurant. Oslo Seasonal boat 2.6 Lille HerbernA small islet right next to Store Herbern, southeast of Bygdøy. Known for a long-established summer restaurant reached by a small ferry from Bygdøy. Oslo Seasonal boat 3.0 GressholmenOne of the most visited islands in the inner Oslofjord, joined by land to Rambergøya and Heggholmen. Norway's first airport opened here in 1927 and served as the country's main airport until 1939. Gressholmen Kro, the island inn, runs through the summer. Several bathing spots, including a naturist area. Oslo Ferrylive 3.1 DynaThe Dyna skerry between Bygdøy and Nakkholmen carries Dyna fyr, a red and white lighthouse building of 12.4 metres from 1874, automated in 1956. Since 1992 it has been run as a restaurant and function venue by Fursetgruppen, and it is one of the best-known landmarks in the inner Oslofjord. Oslo Seasonal boat 3.2 HeggholmenIsland joined to Gressholmen and Rambergøya by infill. Heggholmen lighthouse on the northern tip is the oldest in the inner Oslofjord and is a protected monument. There was industry here once, a steam-driven linseed oil press and soap production, and remains of the workers' housing and the school building still stand. A few private cabins. Oslo Seasonal boat 3.2 NakkholmenState-owned island about 600 m off Bygdøy, densely built with small cabins from the 1920s. There are 182 of them, and their size, colour and appearance are tightly regulated. A shipyard ran here from 1918 to 1952. Open to public access and outdoor recreation. Oslo Ferrylive 3.5 RambergøyaRambergøya covers about 12 hectares (120 dekar) and is joined by land to Gressholmen and Heggholmen, all three inside the Gressholmen-Rambergøya nature reserve. The pine forest on limestone here is among the most intact on the islands of the inner Oslofjord. There are swimming spots. Oslo Seasonal boat 4.2 Nordre LangøyaThe northern part of the bathing island Langøyene in Bunnefjorden. Camping is allowed here. Norway's first cement factory stood on Nordre Langøya from 1837 to 1938. Nesodden Seasonal boat 4.4 LangøyeneA popular bathing island in the Bunnefjord, formally part of Nesodden but owned and run by Oslo. Originally two islands that grew together when the sound between them was filled with refuse: the city dump from 1904 to 1948, cleaned up between 2019 and 2021. Sand beach, camping and a naturist beach. Nesodden Ferrylive 4.7 Søndre LangøyaThe southern part of the bathing island Langøyene in the Bunnefjord. A naturist beach lies at the southern end, and the island is used for swimming and outdoor recreation. Nesodden Ferrylive

The seasonal boat «Undine» out to the Steilene islets. Summer only.

12.2 StorsteilaOne of the islets in the Steilene group off Nesodden. It is a state-secured public recreation area. Nesodden Seasonal boat 12.4 LandsteilaOne of the islets in the Steilene group off Nesodden. A state-secured recreation area, bought for public use, with several buildings of conservation value from the group's older industrial history. Nesodden Ferrylive 12.6 SteileneGroup of five islets in the inner Oslofjord off Nesodden: Persteila, Landsteila, Storsteila, Knerten and Fyrsteila. A state-secured public recreation area with buildings of heritage value from older industry, a coastal trail cabin (*kystledhytte*) in the old lighthouse, and a small-boat harbour, beach and fire pit on Persteila. The name is tied to an old execution site. Nesodden Ferrylive 12.7 PersteilaThe main islet in the Steilene group off Nesodden, and the one with the best facilities: small-boat harbour, beach, showers and a shared fire and barbecue site. A popular anchorage. Nesodden Seasonal boat 13.0 FyrsteilaFyrsteila is the lighthouse island in the Steilene group off Nesodden. The decommissioned lighthouse is run today as a coastal trail cabin (*kystledhytte*) by Oslofjordens Friluftsråd, and it houses “Kunstfyret”, where children meet history, art and nature. Nesodden Seasonal boat

Across Drøbaksundet to Oscarsborg and Håøya. The fortress ferry runs all year, the Håøya boat in summer.

19.8 Søndre LangåraIsland at the northern end of Frogn, about 1.3 km long, with 61 cabin properties. The protected fog bell station stands on the northern tip and can be rented through Kystled Oslofjorden. Frogn Ferrylive 21.6 LågøyaLågøya lies north of Håøya and is about 900 metres long and 13 hectares (130 dekar) in area, with 21 rental cabins, a tennis court and a boathouse. It has been owned since 2022 by the Sparebankstiftelsen DNB foundation and is managed as a public recreation area by DNT Oslo og Omegn together with Oslofjordens Friluftsråd. Frogn Ferrylive 22.3 AspondIsland in the northern part of the Drøbak sound, about 30 hectares (300 dekar) with around 46 cabins. Privately held cabin island; the main shipping lane in to Oslo runs close along its east side. Reached by private boat. Frogn Ferrylive 23.8 Nordre HåøyaThe northern part of Håøya, the large recreation island in the inner Oslofjord owned by the City of Oslo. Walking country and room for tents; harbours include Dragsundet. Frogn Seasonal boat 26.6 HåøyaThe largest island in the inner Oslofjord (5.2 km²), owned and managed by the City of Oslo as public outdoor land, with campsites and several harbours (Sagbukta, Tåjebukta, Dragsundet). Varden, 229 metres above sea level, is the highest point anywhere on the Oslofjord. A gunpowder works stood on Mellomøya during the First World War. It is a popular destination for walkers and boaters. Frogn Ferrylive 26.8 Nordre KaholmenThe northern of the two Kaholmene islets that make up Oscarsborg fortress in Drøbaksundet. The torpedo battery that sank the German cruiser Blücher on 9 April 1940 stood here. Part of the fortress area open to visitors. Frogn Seasonal boat 27.2 KaholmaneThe island group made up of Nordre and Søndre Kaholmen, together Oscarsborg fortress in the Drøbak sound. A national fortress with a museum, hotel, restaurant and opera festival, known for sinking the cruiser Blücher on 9 April 1940. Frogn Ferrylive 27.3 Søndre KaholmenThe main island of Oscarsborg fortress, with the main fort from 1848. Today it is a national fortress site with a museum, hotel and restaurant, and the stage for the Oscarsborg opera every August. Around 100,000 visitors a year. Frogn Ferrylive

Bastøy. The island is a working prison, so access is not open.

61.1 BastøyBastøy is a state-owned island of 2.23 km² southeast of Horten, known for the open prison that has been there since 1988 and for the reform school for boys that ran from 1900 to 1970. It has forest, farmland and beaches, a lighthouse from 1840 and a stone church from 1902. Horten Seasonal boat

Out into Færder national park. Bolærne in summer, Veierland all year.

75.0 TorgersøyaA small island of 0.3 km² in the outer Oslofjord, inhabited from the 1700s until the early 1900s. The lighthouse station dates from 1851 and closed in 1983, leaving a protected bell tower; there are also around 15 cabins and floating docks. Civitan Club Tønsberg runs a campsite with boat transport in summer, and sheep graze to keep the vegetation down. Tønsberg Seasonal boat 78.0 Vestre BolærenThe westernmost of the main islands in the Bolærne group, in the outer Oslofjord off Nøtterøy. Military history from Bolærne fort, after the Norwegian Armed Forces bought the islands in 1916, and most of it lies within Færder National Park. Good for swimming and walking. Færder Seasonal boat 78.2 BolærneAn island group in the outer Oslofjord off Nøtterøy: the three main islands Vestre, Mellom and Østre Bolæren plus some 40 smaller islets and skerries, 2.6 km² in all. Settled since the 1600s, bought by the Norwegian Armed Forces in 1916 for the Bolærne coastal fort, and now one of the region's most visited summer destinations, with a seasonal ferry from Tønsberg. Most of the group lies within Færder National Park. Færder Seasonal boat 78.3 Mellom-BolærenThe middle island in the Bolærne group and the one best set up for visitors, with a seasonal ferry from Tønsberg. Grevestuen, reckoned one of the oldest hunting lodges in Norway, stands here, along with traces of military history. Most of the island lies within Færder national park, and it is popular for swimming and outdoor life. Færder Seasonal boat 79.2 Østre BolærenØstre Bolæren is the easternmost of the main islands in the Bolærne group. It carries clear traces of Bolærne fort and the military installations from 1916, and during the war the Germans ran a camp for Soviet prisoners of war in the area. Most of the island lies within Færder National Park. Færder Seasonal boat 87.7 VeierlandA car-free island of 4.16 km² with around 150 permanent residents and a large number of holiday homes. Ferries run from Tenvik on Nøtterøy and from Engø near Sandefjord. Edvard Munch spent the summer of 1887 here, and Jens Bjørneboe lived his last year in the Swiss-style villa Eikvold. The church dates from 1905. Færder Seasonal boat

The far end of the fjord, more than a hundred kilometres from Rådhusbrygga. Scheduled boats to the car-free islands.

100.2 Nordre SandøyA car-free island in eastern Hvaler with a network of walking paths and a summer café at Makø farm. Old family farms and modern cabins stand side by side, after the fishing industry went. Hvaler Ferrylive 101.3 Nordre LauerPart of the Lauer islands, which historically held an important fish receiving station where catches from the surrounding fishing stations were landed. It is car-free and thinly populated today. Hvaler Ferrylive 102.0 LauerLauer is an island group south of Kirkøy made up of Nordre Lauer, Sva Lauer, Mellomholmen and Sør-Lauer. Nordre Lauer is the main island, with around 34 holiday cabins and a small-boat harbour. It is a popular destination in the outer Hvaler. Hvaler Ferrylive 103.6 HerfølThe southernmost inhabited island on Hvaler, close to the Swedish border, with around 20 permanent residents. Once a fishing station with a customs post and a pilot station, it is now a summer destination with a marina, pub, shop and bathing spot. Protected Bronze Age burial cairns, among them Langrøsset, and the glacial pothole known as Katedralen. Hvaler Ferrylive

A short crossing to the sailing island, which has no road link.

77.1 HankøWell-known sailing island in Fredrikstad, about 4 km². It has a sailing centre with regattas in June and July, the Hankø Fjordhotell, and Bloksberg, the royal family's former holiday property. Bronze Age burial cairns and traces of a German radar station from the Second World War, plus a fallow deer herd of its own. Fredrikstad Seasonal boat

Islands with a boat connection that does not belong to a fixed route.

13.2 LangåraOne of the larger islands in the inner Oslofjord, about 2 km long and 200 m wide. A popular public recreation area with a long tradition of camping summers. The old shop is now a coastal trail cabin (kystledhytte), and Norwegian People's Aid staffs a first-aid post here in summer. Good anchoring in Middagsbukta. Asker Seasonal boat