Spend a few hours exploring the Kastellet, a 17th-century star-shaped fortress. This defensive citadel still hosts military barracks and offices but is also one of the most popular green spaces in Copenhagen. What was once a key part of the city's fortifications is now a place to walk, jog, cycle and unwind.
Enter the historic site via the King's Gate or the Norway Gate. Both of these Dutch Baroque structures were built in 1663. Walk on the grassy ramparts around the fort and take in excellent views of part of the Danish capital, including the harbor and the Little Mermaid, the iconic bronze statue inspired by the fairy tale of the same name by Hans Christian Anderson. During your walk, you will come across numerous canons from different time periods
Browse the citadel’s three museums which cover different aspects of its history. Note that the museums have limited opening hours. Go to the windmill, a 19th-century replacement of the early 18th-century original. Tour the interior of the 18th-century Baroque church. Next door is the old prison complex. Other buildings you may see while inside the fortress are the barracks and a powder house that used to store gunpowder.
Explore the Monument for Denmark's International Effort since 1948, which features an eternal flame and a space to remember the country's fallen soldiers.
At noon watch the Changing of the Guard ceremony at Central Guard House. If you are here during summer, attend a military concert on the drill ground. The concerts take place in the early afternoons. Throughout the year the Kastellet hosts many other events such as military parades and classic car shows. Visit the official website for the Kastellet to see what's on during your stay in the city.
The Kastellet is open daily and admission is free. Drive and use the street parking, available for a fee, or come by public transportation. On foot it it 5 minutes to Osterport train station while Kongens Nytorv metro station is 15-20 minutes away.