
Saltholm (; ''Salt Islet'') is a Danish island in the
Øresund
Øresund or Öresund (, ; da, Øresund ; sv, Öresund ), commonly known in English as the Sound, is a strait which forms the Danish–Swedish border, separating Zealand (Denmark) from Scania (Sweden). The strait has a length of ; its width ...
, the
strait that separates
Denmark
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, song = ( en, "King Christian stood by the lofty mast")
, song_type = National and royal anthem
, image_map = EU-Denmark.svg
, map_caption =
, subdivision_type = Sovereign state
, subdivision_name = Kingdom of Denmark
, establishe ...
and
Sweden. It is located to the east of the Danish island of
Amager in
TÃ¥rnby municipality and lies just to the west of the sea border between Denmark and Sweden. It is 7 km long and 3 km wide, covering an area of 16 km
2, making it Denmark's 21st largest island. Saltholm is very flat; its highest point stands only 2 m (6 ft) above sea level, rendering it vulnerable to flooding if persistent east winds cause a tidal surge in the
Baltic Sea
The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain.
The sea stretches from 53°N to 66°N latitude and fr ...
. It is a relatively new landmass in geological terms, having risen from the sea about 4,000 years ago due to
post-glacial rebound
Post-glacial rebound (also called isostatic rebound or crustal rebound) is the rise of land masses after the removal of the huge weight of ice sheets during the last glacial period, which had caused isostatic depression. Post-glacial rebound ...
, and is surrounded by a large area of shallow water (of 2 m depth or less) that covers an area of . A series of islets, inlets and rock deposits from the last
ice age
An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gre ...
appear at the south end of the island.

Its neighboring island to the south is the
artificial island
An artificial island is an island that has been constructed by people rather than formed by natural means. Artificial islands may vary in size from small islets reclaimed solely to support a single pillar of a building or structure to those tha ...
Peberholm
Peberholm ( , sv, Pepparholm, links=no ()), is a small artificial island in the Danish part of the Øresund strait, created as part of the Øresund Bridge connecting Denmark with Sweden. Peberholm lies approximately 1 km south of the small n ...
(''Pepper Islet''), which is a part of the
Øresund Bridge
The Öresund or Øresund Bridge ( da, Øresundsbroen ; sv, Öresundsbron ; hybrid name: ) is a combined railway and motorway bridge across the Øresund strait between Denmark and Sweden. It is the longest in Europe with both roadway and rai ...
and was named to complement Saltholm.
Flora and fauna

Saltholm's vegetation is dominated primarily by grasses, with its landscape consisting mainly of flat chalk meadowlands and coastal meadow. There are few trees on Saltholm, clustered mainly in two places in the north and south-west of the island.
The island has a rich variety of flora, notably
motherwort (''Leonurus cardiaca''),
henbane (''Hyoscyamus niger''),
blue iris (''Iris spuria'') and
chickweed.
["Saltholm". ''Aschehoug's Leksikon''. Aschehoug (Egmont), 2008]
Saltholm is a protected nature reserve for wild birds which nest in large numbers on the island. The southern part of the island, an extensive
salt marsh
A salt marsh or saltmarsh, also known as a coastal salt marsh or a tidal marsh, is a coastal ecosystem in the upper coastal intertidal zone between land and open saltwater or brackish water that is regularly flooded by the tides. It is domin ...
, is protected under the
Ramsar Convention
The Ramsar Convention on Wetlands of International Importance Especially as Waterfowl Habitat is an international treaty for the conservation and sustainable use of Ramsar site, Ramsar sites (wetlands). It is also known as the Convention on W ...
and the island as a whole, along with the surrounding area of sea, has been designated a nature reserve by the
European Union
The European Union (EU) is a supranational political and economic union of member states that are located primarily in Europe. The union has a total area of and an estimated total population of about 447million. The EU has often been ...
.
Mussel
Mussel () is the common name used for members of several families of bivalve molluscs, from saltwater and freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other edible clams, whic ...
beds,
eel grass, snails, crustaceans and fish in the shallow waters around the island provide an important food source for water birds. Because of its importance as a wildlife sanctuary, access to Saltholm and its surrounding waters is strictly controlled. Access to the island is via a small harbour at Barakkebro, at the north end of Saltholm.
The island is Denmark's largest grazing area for geese, some 7,000 of which visit during the summer. Around 3,500 juvenile swans also live on the island in the summer, with some 2,000 wintering there. 10,000–12,000 ducks breed and graze on Saltholm during autumn and late winter/spring. Saltholm is also home to Europe's largest breeding colony of
eider
Eiders () are large seaducks in the genus ''Somateria''. The three extant species all breed in the cooler latitudes of the Northern Hemisphere.
The down feathers of eider ducks, and some other ducks and geese, are used to fill pillows and qu ...
s; 15,000 live on the island during the spring and some 7,000–8,000 are hatched on the island each year.
File:Aerial view of Saltholm - 1.jpg,
File:Aerial view of Saltholm - 2.jpg,
File:Saltholm and Oresund bridge.jpg,
History

Humans have lived in small numbers on Saltholm since the Middle Ages and probably before. The population has decreased from a peak of 298 people in 1916, when the island was fortified during
World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was List of wars and anthropogenic disasters by death toll, one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, ...
, to two people .
The existence of the island is first attested in 1230, when King
Valdemar II of Denmark
Valdemar (28 June 1170 – 28 March 1241), later remembered as Valdemar the Victorious (), was the King of Denmark (being Valdemar II) from 1202 until his death in 1241.
Background
He was the second son of King Valdemar I of Denmark and Sophia ...
is recorded as having given Saltholm to Bishop
Niels Stigsen
Niels is a male given name, equivalent to Nicholas, which is common in Denmark, Belgium, Norway (formerly) and the Netherlands. The Norwegian and Swedish variant is Nils. The name is a developed short form of Nicholas or Greek Nicolaos after Saint ...
of the see of
Roskilde
Roskilde ( , ) is a city west of Copenhagen on the Danish island of Zealand. With a population of 51,916 (), the city is a business and educational centre for the region and the 10th largest city in Denmark. It is governed by the administrative ...
. For centuries, the island was used to quarry
limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms wh ...
, which was used in nearby
Copenhagen
Copenhagen ( or .; da, København ) is the capital and most populous city of Denmark, with a proper population of around 815.000 in the last quarter of 2022; and some 1.370,000 in the urban area; and the wider Copenhagen metropolitan ar ...
and elsewhere; in 1289, the town lord of Copenhagen is recorded to have granted quarrying rights on Saltholm and quarrying continued until as late as 1935.
The island was also traditionally used as pasture land for the cattle of the people of the nearby Danish island of
Amager. The cows of Saltholm were commemorated in the late 19th century by the Danish painter
Theodor Philipsen, who travelled frequently to the island to paint its cattle and treeless landscapes.
Saltholm was used as a
quarantine
A quarantine is a restriction on the movement of people, animals and goods which is intended to prevent the spread of disease or pests. It is often used in connection to disease and illness, preventing the movement of those who may have been ...
station between 1709 and 1711 when Copenhagen suffered
plague
Plague or The Plague may refer to:
Agriculture, fauna, and medicine
*Plague (disease), a disease caused by ''Yersinia pestis''
* An epidemic of infectious disease (medical or agricultural)
* A pandemic caused by such a disease
* A swarm of pes ...
and
cholera outbreaks. Travellers wishing to land in the city were required to stay in quarantine on the island for 40 days. In 1873, a private company, the Saltholmlaug, acquired the island from the state and still owns it today.
The island's position in the middle of the Øresund gave it some military significance during the two World Wars. In 1912, the Danish government constructed the
Flakfortet (sand-shoal fort) on the Salthom Flak sands just north of the island proper, stationing a number of artillery pieces ranging in calibre from 47 mm to 290 mm. Most of the guns were mounted on
barbette
Barbettes are several types of gun emplacement in terrestrial fortifications or on naval ships.
In recent naval usage, a barbette is a protective circular armour support for a heavy gun turret. This evolved from earlier forms of gun protectio ...
carriages and protected by armoured shields and concrete and earthen ramparts. The fort was still active at the start of
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...
; although old, its guns were still seen as a strong deterrent.
Saltholm was the site of an incident resulting in the loss of the British submarine
HMS ''E13'', which ran aground on the island on 17 August 1915 due to a faulty compass. Two days later, two German destroyers attacked the submarine while it was still stranded on the shoreline as the crew worked to refloat the vessel. Fifteen of the submariners were killed before Danish torpedo boats intervened to deter the attackers. The violation of the country's neutrality outraged the Danish government, prompting a diplomatic protest to the Germans, and the casualties were given high-profile official funerals by the Danish navy. The surviving crew were interned in Denmark until the end of the war in November 1918, and the wrecked submarine was scrapped. The commander of the ''E13'', Lt Cdr
Geoffrey Layton, went on to have a distinguished career in the
Royal Navy
The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by Kingdom of England, English and Kingdom of Scotland, Scottish kings from the early medieval period, the first major maritime engagements were foug ...
and commanded the British
Eastern Fleet
Eastern may refer to:
Transportation
*China Eastern Airlines, a current Chinese airline based in Shanghai
* Eastern Air, former name of Zambia Skyways
*Eastern Air Lines, a defunct American airline that operated from 1926 to 1991
* Eastern Air ...
during the Second World War.
The island was for many years considered as a possible location for a new international airport and fixed link between Denmark and Sweden. The nearby
Copenhagen Airport
Copenhagen Airport, Kastrup ( da, Københavns Lufthavn, Kastrup, ; ) is an international airport serving Copenhagen, Denmark, Zealand, the Øresund Region, and southern Sweden including Scania. It is the second largest airport in the Nordic ...
at
Kastrup
Kastrup () is a suburb of Copenhagen, Denmark, on the east coast of Amager in Tårnby Municipality. It is the site of Copenhagen Airport. In Danish, the airport is often called ''Kastrup Lufthavn'' (Kastrup Airport) or ''Københavns Lufthavn, Kast ...
has long been the busiest airport in Scandinavia but has suffered from an acute shortage of space and its proximity to built-up areas. In 1965, the
Nordic Council
The Nordic Council is the official body for formal inter-parliamentary Nordic cooperation among the Nordic countries. Formed in 1952, it has 87 representatives from Denmark, Finland, Iceland, Norway, and Sweden as well as from the autonomo ...
agreed in principle to build a new international airport on Saltholm, to replace the airport at Kastrup, and to construct a bridge-and-tunnel link across the island to connect Copenhagen and Malmö. The proposal was strongly supported by
Scandinavian Airlines System, the main user of Copenhagen Airport. The plan envisaged building two pairs of runways, which would carry up to 20 million passengers a year by 1990. A bridge would connect it to Malmö and a tunnel would link to Kastrup on the Danish side. The project was costed at the equivalent of £250 million in 1967 (£3.1 billion / €3.4 billion at 2009 prices).
The plan was approved by the Danish parliament in 1969 with completion scheduled for 1985. However, it was repeatedly delayed; contributory factors included the
1973 oil crisis and its economic fallout, a slump in air travel, and opposition from campaigners concerned about the impact on the fragile environment in the Øresund and around the island. The plan was abandoned in 1979 and further investment was made in
Copenhagen Airport
Copenhagen Airport, Kastrup ( da, Københavns Lufthavn, Kastrup, ; ) is an international airport serving Copenhagen, Denmark, Zealand, the Øresund Region, and southern Sweden including Scania. It is the second largest airport in the Nordic ...
instead.
[Jim Berry, Stanley McGreal, ''European Cities, Planning Systems and Property Markets'', p. 166. Taylor & Francis, 1995. ] When the
Øresund fixed link was eventually built in the 1990s, it was routed 1 km south of Saltholm to avoid damaging the island and the surrounding shallow waters.
See also
*
List of Danish islands
Further reading
* Niels Houkjær: ''Saltholm'' in ''De danske øer - En lystrejse til Danmarks småøer'', S. 151 ff., Nordisk Forlag A/S, Kopenhagen 2006,
References
{{Denmark islands
Islands of Denmark
TÃ¥rnby Municipality
Øresund Bridge
Geography of Copenhagen
Øresund