The construction of Kastellet (the citadel) was started by King Christian IV of Denmark as far back as 1626 with the building of an entrenchment in the northern part of the defense wall of Copenhagen.

Kastellet is a peaceful, protected area, functioning as a military area, a cultural-historical monument, a museum and a park. It is located close to the statue of the popular tourist attraction, Hans Christian Andersen’s The Little Mermaid (Den lille havfrue), the Gefion fountain (Gefionspringvandet) and Langelinie. It is a popular place to go for a walk on a sunny day.