On Ertholmene, wind-swept rocky coast, shady forests and gardens lie just a few hundred metres apart. Birdlife and fortress history meet here, too: on Christiansø and Frederiksø, distinctive towers recall the former defensive fortifications. When planning your trip, consider both the seasonal ferry services and whether you are mainly interested in observing nature or discovering the islands’ history.
Getting there and seasonal ferry services
Christiansø can only be reached by the Christiansø ferry. It departs from Gudhjem harbour, and the crossing takes about an hour. During the peak season, the Ertholm ferry sails to Ertholmene up to three times a day. In winter, the Peter mail boat runs twice a day on weekdays. The service therefore varies by season and day of the week. Check the current timetables before travelling and factor the crossing into your plans.
Getting there is therefore an important part of deciding to visit Ertholmene. The travel times and frequencies given describe different aspects: the approximately one-hour crossing applies to the Christiansø ferry, while the number of daily sailings varies depending on the season and the vessel.
Island nature and birdwatching
The landscape is shaped by the close succession of rocky coast, forest and gardens. Wildlife can also be seen in different places: thousands of eider ducks nest on the inhabited islands, even beside busy roads. In spring and autumn, numerous migratory birds visit Ertholmene, including cranes and goldcrests. A total of 302 different bird species have been observed; that number may grow as further observations are made.
When it comes to breeding birds, it is important to distinguish between recorded species and those that breed regularly. Over time, 52 breeding bird species have been recorded on Ertholmene, but only 25 species breed regularly on the islands. There are also more than 15,000 breeding pairs. The many pools provide habitats for amphibians, including toads and newts as well as the rare European green toad and moor frog.
Græsholm is a bird sanctuary and closed to the public. The island is home to one of Denmark’s largest seabird colonies; the birds can be observed with binoculars from Frederiksø. Up to 400 resting grey seals were reported on Ertholmene in 2013. The island group is one of the largest haul-out sites for this seal species. Nature here encompasses everything from migratory and breeding birds to seal haul-out sites, although Græsholm itself cannot be visited.
The awards also refer to different points in time: in 2018, Ertholmene was included as one of 15 places in the Kingdom in Denmark’s Nature Canon, the official list of Denmark’s most beautiful places. In 2020, the Danish Outdoor Council designated Christiansø an official nature reserve.
Fortress history on Christiansø and Frederiksø
The natural harbour between Christiansø and Frederiksø was decisive in the choice of location: in 1684, King Christian V chose Ertholmene as the site for his naval fortress. The distinctive Store Tårn on Christiansø and Lille Tårn on Frederiksø were originally built as the fortress’s central defensive structures. Today, both house museums.
Store TĂĄrn brings together fortress and lighthouse history: a lighthouse dating from 1800 is integrated into the tower, and Store TĂĄrn underwent a complete renovation from 2014 to 2018. Through its exhibitions, Lille TĂĄrn focuses on local military and cultural history. The two museums are on different islands and complement each other with their respective themes.
Another cultural stop is Palivaren at Juuls Bastion on Christiansø. During the summer season, artists exhibit and sell their work there. Nature watching, fortress buildings and the seasonal gallery offer different reasons to discover Ertholmene. You can match whichever interests you most to your travel dates and the available ferry services.
For the wider travel overview: Denmark.
