Arriving in Copenhagen, head first to its historic district—Indre By. Here, you can admire old buildings, wander through quiet narrow streets, and vividly imagine what the city looked like centuries ago.
The Christianshavn district is notable for its canals and the "free town" of Christiania. In the Østerbro district, you’ll find the Kastellet citadel, while Vesterbro is full of interesting cafés and bars. The most picturesque part of Copenhagen is Nyhavn (New Harbour), where artists, poets, and other representatives of the creative bohemia reside.
You may also want to see the city's symbol—the famous Little Mermaid statue. It is located at the entrance to the harbor and can be reached via suburban Re-tog trains or city S-tog trains. After getting off at Østerport station, head towards the Langelinie promenade and follow the signs marked "Lille Havfrue."
Be sure to set aside time to visit Amalienborg Palace, the official residence and home of the Danish royal family. Every day around noon, you can witness an impressive spectacle—the changing of the guard at its gates.