Nature and environment

Drøbak is an exciting combination of a rich maritime environment and a fertile landscape surrounding the Drøbak Strait – very near to the nation’s capital Oslo.

"Biologen" kan stå som et symbol på det rike biologiske mangfoldet rundt Drøbak, og den forskningen som dette danner grunnlag for. Foto: Tore Lundby.

The Marine-Biological Research Institute building at the Drøbak waterfront. A symbol of the great natural diversity found in the area. Photo: Tore Lundby.

Drøbak is an exciting combination of a rich maritime environment and a fertile landscape surrounding the Drøbak Strait. The municipality of Frogn has altogether 60 kms of coastline to the Oslo Fjord, where also 43 big and small islands are situated. The Fjord and the nature & agricultural landscape around Drøbak is altogehter an ”eldorado” for hikes and nature experiences. And all this is to be found just half an hour away from the norwegian capital.


Mange får oppleve miljøet i Drøbaksundet, noen fra cruiseskipenes dekk.

Many cruise ships pass through the Drøbak Strait every year in one of Norway’s richest seawater environments.


The Oslo Fjord and the Drøbak Strait

Just outside Drøbak, where the Oslo Fjord is at it’s most narrow, approximately 5.500 ships of all sizes sail by through the year. This fleet carries 6 million tons of merchandise and 2,6 million passengers to Oslo turn/return. Under the water, some 5000 cars pass in the Oslo Fjord Tunnel every day. In addition comes the swarm of sailboats and motorcruisers using the Oslo Fjord for leisure all year – mostly in the summer months. This may sound very busy, but the truth is that the Fjord offers relax and recreation to a great number of people throughout the year. In the middle of Norway’s most densely populated area, everybody is welcome to enjoy sea and nature. The sea water is clean and well suited for swimming. This is the fruit of a long-lasting effort to tidy up deposits of previous industries and public sewers. Today, there is a strict control of spills and outlets, no waste is dumped in the sea.


Det rike livet i Drøbaksundet frister til båe fiskeing og dykking. Foto: Adreas Trøite.

The rich marine life i the Drøbak Strait makes fishing and diving very attractive. Photo: Adreas Trøite.

Norway’s most diversified marine environment

The strait outside Drøbak is one of the most desired fish areas in the country. Just see if your fish are biting! The water currents create a rich mix of nutrition, and the complex sea bottom forms biotops for numerous species of fish, sea animals and plants. Some 100 different species live here, creating the most varied range of sea life in the whole country. The green sea porcupine (Strongylocentrotus droebachiensis) has been named after Drøbak. Many sports divers find great excitements in the sea bed outside Drøbak.

You may experience this rich variety visiting the Drøbak Aquarium. 24 different bassins display the versatile life in the Fjord outside.



Håøya – ”the holy island”

Håøyas søndre del er vernet villmarksområde, uberørt av menneskelig aktivitet.

The southern part of “The Holy Island” is a wildlife & nature reservate, untouched by human activities..

Håøya is the biggest island in the inner Oslo Fjord (5,6 km²) and id situated northwest of Oscarsborg Fortress. The island is situated in Frogn municipality, but is owned by the City of Oslo. The whole island is a recreation area. The southern part is a special reservate with many rare plant species. The island was shut off as a military area for generations, and has few signs of human activities. Some can be observed: On the southern top there are remains of huge cannon foundations, and the ”gun-road” can be seen clinging to the east side of the island. Animals live an undisturbed life here, with the moose as the king of the island. Even a sea eagle couple has nested in the rugged western rock formations, breeding offspring for the first time in 126 years. This happened in 2008. This part of the island is today under heritage protection and completely shut off for public entrance. But you can view this wildlife  environment in a distance.

The middle and northern part of Håøya is open to the public, and a great camp site is found here. More info and photos: This website presents an overview of all the islands in the inner Oslo Fjord.


Charterfergen "Jacobine" passerer gjennom åpningen i jetéen.

The Charter Ferry “Jacobine” passing through the narrow gate in the undewater stonewall.

The “Jetée” – defence history and biotope

Håøya divides the Oslo Fjord in two straits. In order to concentrate Oscarsborg’s firepower in the eastern strait, an underwater stonewall was built in the western strait by convicts in the period between 1875–1905. This effectively stopped larger ships in choosing the western lead. The stonewall is still there, and with it’s rich underwater flora and fauna it is a desired attraction for divers. OBS: Even smaller boats need to cross this underwater stonewall through it’s openings, being marked by buoys: One in the west alongside the shores of Hurum, the other south of Oscarsborg. The wall is of great danger if neglected at low tide, especially for fast speedboats!


Bergholmen er til stor glede for båtfolket. Her feirer den yngre garde i Drøbak Båtforening Kaptein Sabeltanns skattkiste under høstfesten 2011.

Drøbak Boating Club has an annual autumn barbeque at Bergholmen with lots of fun for kids and youngsters.

Bergholmen – a released pearl

Bergholmen is an island in the Western Fjord south-west of Håøya. Also this island was part of the military fortifications, but is today released for bublic use. The island with it’s buildings and docks is being maintained by the local boating societies. The island is a popular harbour for visitors by boat. Summertime, a herd of goats is deployed here to keep the vegetation tidy, in cooperation with the University of Environment and Biology (UMB) in Ås.


Det drives mye fritidsfiske utenfor Drøbak. Måkene venter (forgjeves?) på at Ski Havfiskeklubb omsider skal sløye fangsten.

The seagulls wait for their share of fish guts during the winter fishing season.

Boat life and fishing

Sprellfersk, nyskivet torsk og en stor havabbor. Vinterfisket i Drøbaksundet gir mange gode fangster.

Fresh Codfish and a very large Sea Bass. Winter fishing at Drøbak brings superb seafood on the table.

You are free to travel anywhere in the Oslo Fjord by private boat. For guest harbours, see here. The area around Drøbak provides many sites for fishing from shores and piers. Sloping rocks along the shoreline also offer tremendous possibilities of a good catch. Codfish up to 10 kilos have been caught by rod here, if ”fish stories” are to be beleived … Fishing by rod or line in the fjord is absolutely free (unlike fishing in sweet water, where a fee normally is required).

The most common catch of fish in the Drøbak strait is: Cod, coalfish, pollock, ling, haddock, whiting, hake, blue whiting, ballan wrasse, cuckoo wrasse, grey gumard, mackerel, garfish, herring, sea bass, sea trout, salmon, plaice, common sole, witch, flounder, lemon sole (and many other ”fltafish”). Various kinds of smaller sharks and skates are also common. For more info: /


Fishing by nets is regulated in Norway. See:


Rikt artsmangfold: I Akvariet i Drøbak finner vi denne store hummeren, som er fanget i Drøbaksundet.

This large Lobster may be seen at the Aquarium. It has been caught in the Drøbak Strait.

Fishing of lobster is strongly regulated and only legal between october 1st – november 31st. Various kinds of crabs can be caught and eaten all year. For info of fishing regulations, see:


The Ocean Fishing Club is active all year round in the Drøbak strait, see:


Free delicacies from the sea

Billigere og bedre delikatesse en ferske blåskjell finnes ikke. Men sjekk med blåskjellvarselet før du spiser dem, for skjell kan være giftige i perioder med algeutvikling i sjøen.

Blue Mussels – a delicacy, easily found in the fjord.

Blue mussels are common everywhere in the Oslo Fjord. Make sure they grow on rock in an area with a good current of fresh water. You are free to harvest as much as you like. But remember that blue mussels are naturally poisonous part of the season due to algae that also developes in the sea water. This is an absolutely natural prosess that has nothing to do with pollution! You will find information about poisonous mussels in various areas around the coast, here: :

How to cook Blue Mussels à lá Drøbak

For visitors from abroad, we have this quick-step recipy for cooking blue mussels: Use a wide kettle with a lid. Add some olive oil, let big chuncks of onion and garlic fry for a minute. Put the mussels in the kettle with a dash of dry white wine (not too much, as the mussels contain sea water that will join the ”bouillion” as the mussels open during cooking). Some fresh basil leaves are suitable, but are not a must. Put the lid on, let the mussels steam for 5–10 minutes or until they open. Stir the mussels around to make sure all get well cooked. Serve the mussels straight from the kettle, or add a good dash of cream and taste the greatest soup ever!


Stadig fler opplever Drøbaksundet og indre Oslofjord med kajakk – sommer som vinter.

Paddling is a popular activity near Drøbak all year round. Photo: Drøbak Kajakklubb.

Kayaking in the Oslo Fjord

A steadily increasing number of kayaks are to be seen in the Fjord, summer and winter alike. Not harming the environment at all, and very peacefully – they find their way into all the tempting ”secret” inlets that the coastline around Drøbak offers. At the moment there is no kayak rental in the area, so you have to bring your own. For info, contact:


”Biologen” – the Marine Biological Research Station

Historisk bilde av "Biologen" fra tiden rundt år 1900.

Historic picture of the Biological Reserach Station dating back to ca. 1900.

This institution was established already i 1984, and is today part of Oslo University. One of the entrepreneurs at the time it was opened, was Fridtjof Nansen – the famous polar explorer and humanist. His doctorate was based on scientific findings in the marine environment in the Oslo Fjord.

Tollboden er i dag i bruk til maritim forskning.

Also The Toll Station is today used for marine science.

Today, Biologen is the centre of field cources and worldwide recognized scientific research, all organized by the University of Oslo. In cooperation with the Aquarium, Biologen offers courses for schools. Drøbak Aquarium, run in cooperation with Biologen, is the most visited attraction in the whole Akershus County, and is visited by almost 100.000 pupils from different school levels every year.


Storskjær midt i Drøbaksundet fotografert tidlig om våren. Skjæret er ett av flere hekkesteder for tjeld, gås, måke, ender, ærfugl og flere andre sjøfugler. I hekketida skal vi ikke gå i land!

Storskjær midt i Drøbaksundet fotografert tidlig om våren. Skjæret er ett av flere hekkesteder for tjeld, gås, måke, ender, ærfugl og flere andre sjøfugler. I hekketida skal vi ikke gå i land!

Bird life in the Oslo Fjord

Fiskemåke med dagens fangst. Foto: Andreas Trøite.

Seagulls with “today’s catch”. Foto: Andreas Trøite.

Birds like seagulls, oystercatchers, terns, common eider, ducks and geese breed their offbring on the islands and skerries in the Drøbak strait. A numerous group of cormorants, who normally live far to the north, have also been mating here for the last years, and heron has been observed along the shores. A pair of swans live in Drøbak Harbour. Seabirds in general are under pressure along the coast of Norway, and some are diminishing. Therefore: Be careful, let the seabirds live in peace, admire them in a distance.


Along the shores

Stokkender koser seg i fred i vårsola. Foto: Andreas Trøite.

Mallards in the Early Spring. Photo: Andreas Trøite.

The law states that you are free to walk along all shores in Norway. Some places there will be obstacles because of houses, piers and other constuctions made earlier on, but by principle you are allowed to walk anywhere possible. In Drøbak there are several beaches well fit for swimming: Skiphellebukta, Elleskjær, Torkildstranda, Nordstranda, Parrstranda – and Badeparken (The Seaside Park near the town centre). The water is clean everywhere, with a summer time temperature normally up to 22 centigrades.


The cultivated landscape

Follo Museum er verdt et besøk!

Follo Museum – well worth a visit!

From Drøbak, the hills rise steeply and flatten at a ”plateau” – a moraine built up by glaciers in prehistoric times. This fertile landscape has provided livelihood for a farming population ever since the early Iron Age. The name ”Frogn” derives from ”fraun” which is old nordic, meaning ”fertile soil”. This landscape gives a very nice impression if you walk, ride a bicycle or drive MC or motorcar.

The Follo Museum is a regional institution situated at Seiersten, some 2 kms east of Drøbak. The Museum displays farming, traditional culture and local history. A Museum shop and a café is open for public at the museum. More info:


Skigleder hører med i Drøbak! Klipp fra en film laget av Frognmarkas Venner.

Joy of skiing during winter time around Drøbak! Film cuts from a movie made by “Friends of The Frogn Nature”.

Forests and fields

Skogens konge trives i Frogn. Foto: Andreas Trøite.

The Moose – “King of the Forest” is often seen around Drøbak. Photo: Andreas Trøite.

In Norway you are legally admitted to walk in all forests and fields, except agricultural land in the period when crops are grown between april/may and october. The natural surroundings of Drøbak provide a nice landscape for hikes and not least winter time skiing. Everybody is free to pick flowers, berries and mushrooms.

Ekornet er et kjært syn i skogens mangfold i Frogn. Foto: Andreas Trøite.

The Squirrel is a popular view in the forests around Drøbak. Photo: Andreas Trøite.

Wildlife is rich. The moose, king of the forest, is often to be seen, and herds of deer frequently visit gardens and town premises. Squirrels, foxes and badgers are common, and the deeper forests even give shelter to the shy and mysterious lynx. The rich bird life attracts ornitologists looking for rare species in the Frogn and Drøbak region. More info about outdoor life in forest and fields at:


Across the Drøbak strait lies Hurum, a great peninsula between the Oslo Fjord and Drammen. Larger parts here are ”forgotten” areas with deep forests, hills, marshland and sea shores. Experience the unexpected – this enriches your stay in Drøbak! More info:


Skiløpere på jordene ved Heer. I Frogn har vi naturgleden rett utenfor husdøra! Foto: Tore Lundby.

Cross country skiing in the fields at Heer, near to Drøbak. We have lots of natural splendour right outside the door! Photo: Tore Lundby.

Nature with culture

All these environmental and natural splendours provide recreation and adventure for a large local population. We wish visitors from all over the world welcome, but please be careful and conciderate:

• Leave shores and forests clean and tidy after your visit.

• Do not throw cigarette ends on the ground.

• Curb your dog!

• Release the small fish, leave it to grow up.

• Remember 5 knots speed limit until 200 meters from land.

• Pay attention at sea to smaller boats and kayaks.

• Respect the bird and nature protection areas.

• Pay great attention to pedestrians and bicyclists along the narrow and curvy country roads.

• Do not lit open fires in forests or fields during summer time.


Enjoy environment – welcome to Drøbak & Frogn!