In central Copenhagen, you will find these three lakes lined up that connect several districts. Around the water, there is a beautiful path along which you can walk or bike. The full path is approximately 6 km, but you can also choose to cross some of the bridges and just walk around a few of them.
This is a great way to see all parts of Copenhagen, all the way from the family-friendly Østerbro with huge villas, through the bohemian Nørrebro, through fancy Frederiksberg and rough Vesterbro. Along the way, many small bars, cafes and restaurants are located. If you are walking here during the summertime, you will see all the young Danes throw a big street party with music and beers at Dronning Louise’s Bro (Queen Louise’s Bridge).
On the Nørrebro side, there is a nice restaurant with a floating dock where you can have a refill during your walk. At the same place, you can rent a pedal boat and take a tour of the lake. During cold winter days people ice figure skating (even though I am not sure I would trust the ice).