Copenhagen is one of my favoirte cities with plenty of attractions..just to name a few:
Roskilde Cathedral : Comissioned in the middle ages the Cathedral serves as a mauseleum to the monarchy.
Viking fort at Trelleborg: This for is supposedly erected by teh Vikings in 980AD:
Hans Christian Andersons Home and the ittle Mermiad statue
Nyhavn: the harbour area with bars and cafes perfect for a summer day.