Copenhagen, the largest city in the Oresund Region (Øresund if you're Danish, Öresund if you're Swedish) and the capital of the Kingdom of Denmark, is a very good option for those travelers in Europe who would like to experience something different than the usual city destinations in the largest countries.

During the summer months, Copenhagen has a pleasant and lively atmosphere. Most of these sights won't be as fun during the dark and cold winter months. In general, I wouldn't recommend visiting any of the Nordic capitals during the dark half of the year (October - March). There are many more sights, more than expected actually, in Copenhagen so you won't be restless.

Nyhavn

Nyhavn is probably the most popular sight in Copenhagen and if you have plans on visiting it's highly likely that Nyhavn is a big part of why you got interested to begin with, and if not then now you know that this is the major attraction here. You won't miss it though. Nyhavn is in the center of the city, near Kongens Nytorv (Danish; The King's New Square) which is a central point of the city where many of the major roads start or end. The name Nyhavn means "New Harbor" in Danish and as the name might suggest it is not a natural harbor.

Nyhavn was built between 1670 - 1675 and it was dug by Swedish prisoners of war. For several hundreds of years it was an important commercial harbor for the Danes but when ships grew too large in the early 1900s the harbor became almost abandoned and dilapidated. It wasn't until the 1980's that it became a popular tourist destination when the quay was pedestrianized. Today Nyhavn is filled with restaurants and tourists taking pictures. You get the best views from the southern side of the quay or Nyhavnsbroen (Nyhavn Bridge). Inderhavnsbroen (The Inner Harbour Bridge), connecting Nyhavn to Christianshavn, also offers good views of the harbor.

Den Lille Havfrue

Nyhavn might be the most popular sight for tourists to Copenhagen, but the most famous is the small statue called Den Lille Havfrue, or as it's known in English: The Little Mermaid.

The statue, depicting a mermaid and based on the 1837 fairy tale of the same name by Hans Christian Andersen, is only 1.25 meters (4.1 ft) tall and rather small. It was unveiled in 1913 and has since then been a popular sight and almost become a symbol of the city. The negative with this statue is that the location is quite off. It's a fairly long walk from the center of the city and the rest of the attractions that this city has to offer. It's located in the area known as Langelinie (Long Line), which is a park complex along the shore. There are some other sights you can do while in the area. Kastellet (The Citadel) is a preserved old fortress that is open for visitors for example.

Despite the small size and inconvenient location, this is still one of those things you just can't miss. You can't truly claim that you've been in Copenhagen unless you've seen The Little Mermaid. Just don't expect too much. Go and see it, but you'll be on your way towards something else very quick.

Strøget

Strøget is the main street of Copenhagen, and it's one of the longest pedestrian streets in Europe at over 1 kilometer in length. The street starts at Rådhuspladsen (City Hall Square), near the Central Railway Station and Tivoli, and it ends at Kongens Nytorv. Along the way, it passes through or near some of the other sights of the city such as Gammel Torv and Nytorv (Old Square and New Square).

When it comes to the selection of stores on Strøget it's pretty much the same as on similar streets in Europe. The same high-end chains and an over-establishment of souvenir shops. But you're not there for shopping, the reason you should walk up and down this street is to experience the street life and vibe of the city. It is also the most convenient way to travel between many parts of central Copenhagen.

One of the streets you will eventually encounter while walking down Strøget is Købmagergade which is another major pedestrian street in Copenhagen and one that's also worth exploring. On this street you will for example find the 17th century Rundetårn, known for having an equestrian staircase. It's open to the public and it doesn't take much time to walk up and enjoy the view.

Nørrebro

Northwest of the city center there's an area called Nørrebro which is known for having a lot of public art, often with political undertones. The area also has an active restaurant and nightlife scene, and it's very multicultural which has a visible effect on the selection of establishments you can choose from if you decide to come here for a meal. The area has in recent years been prone to riots connected to youth culture, but as a tourist you will likely not see or be involved in any of that

If you just want to get a feeling for the area you can do what I did and take the metro to Nørrebro Station and then just walk the full length of the main street, Nørrebrogade (Nørrebro Street), back to the city center. This way you will pass through many of the sights and you'll also see much of the life in the area during your more than 2 kilometers (1.2 miles) long walk. After you've walked over Queen Louise Bridge you are once again back in the city center (also called Indre By).

Assistens Cemetery is a focus point of the area and a popular green space. Many famous Danes are buried there, most famous is probably H.C. Andersen, the same author who wrote "The Little Mermaid".

Christiania

Not really my type of destination and definitely not a pleasant place. Be careful here! At the same time, Christiania is such a unique and famous place that you can't ignore it.

Pusher Street is the main street and the only place where things really happen. Apart from Pusher Street Christiania is actually quite sleepy and you will find yourself to be mostly alone if you wander away from that street.

There's a lot of interesting graffiti and mural works to see but be careful if you want to take pictures. There's a ban on photography in the area and especially on Pusher Street you will attract bad attention if you try to take pictures. I was able to take some pictures of the graffiti and murals in the quieter parts of Christiania but I put it down whenever there were people around, which there will be on Pusher Street. Despite the reputation this part of Copenhagen has it's actually a rather integrated part of the city fabric.

While you're here, take some time to explore the full Christianshavn area. It's a much more pleasant area in general and you can find some good architecture as well as taking a nice stroll along the canal that cuts through the island.