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Ertholmene Archipelago

History of the Islands

Bornholm fishermen have used Ertholmene as a temporary shelter since the Middle Ages. The first permanent residents appeared as a result of the Danish-Swedish conflicts at the end of the 17th century.
As Denmark needed a naval base in the middle of the Baltic Sea, a fort was built on Christiansø and Frederiksø in 1684, which served as an outpost for the Danish Navy until 1855. The Church on Christiansø originally served the garrison. The island population peaked in the 1810 census with 829 inhabitants. They were soldiers who were there because of the gunner war.

Many of the historic buildings now serve as living quarters for the local population, and some of them are rented to summer tourists. The outer appearance of the islands has changed very little in over 300 years. Surrounded by thick granite walls with old cannons pointing towards the sea, Christiansø is a picturesque tourist spot seemingly frozen in time.

Formerly part of the fort, Store Tårn has been home to the Christiansø Lighthouse for 200 years, and Frederiksø's small round tower, Lille Tårn, is a museum.

Discovery of the Islands

The islands were "discovered" by artists, especially painters, who, captivated by the raw beauty of the islands, began to settle there - even today a small group of them live there permanently. The construction of new buildings and interference with the existing state of the island is prohibited, and all this to keep the island as it was in the times of Christian V - for example, TV antennas are hidden inside the buildings.

Unprecedented nature, picturesque local architecture, remains of old fortifications, and above all, the unique character of the islands attract over 80,000 tourists every year.


Unlike Christiansø and Frederiksø, Graesholmen has never been inhabited.

When in 1684 the plague of the dead was spreading among the men working on the construction of the fortress, the dead were buried in the Plague Cemetery on Graesholmen.

Today, Graesholmen is an ornithological reserve, where auks and guillemots have their breeding grounds here - it is the only such place in Denmark. In the bird sanctuary of Greensholm, around 10,000 pairs of silver gulls and an alk inhabit this only place in Denmark. During spring and autumn, millions of small birds migrate across the Baltic Sea to the breeding areas in the north, while large numbers of migratory birds seek food and rest on Christiansø before continuing their journey.

The island is closed to visitors.

Reklama Bornholms Museum

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