When visiting the Little Mermaid, venture into this territory in the form of a five-pointed star. Formerly a military fortress, Kastellet has now become a pleasant place to walk.

In the centre of the star you'll find red buildings, the original barracks and, at one end, a well-preserved windmill in the lining of the cannons.

What to see in the citadel?

The interior of the Kastellet Citadel can be reached through two gates from the north and south. The grounds are free to walk through and you can admire the original red barracks built between the 17th and 19th centuries.

Some of them are still used for military purposes, others have been converted into ordinary apartments. You can't get inside the buildings, with the exception of a few small cafes that operate here.

The fortress walls are grassed and freely accessible around the perimeter. Walk around them and visit the small windmill at the western end of the fort.