Copenhagen is a city rich in history, and this is reflected in its buildings. Many of Copenhagen's most impressive historic sites date from the 16th and 17th centuries and were built during the reign of King Christian 4, a renaissance ruler often referred to as the 'builder king' for his ambitious vision of a Copenhagen filled with tall spires. Today, these can be seen on the Round Tower of the Latin Quarter, the old stock exchange Børsen and King Christian's former summer residence, Rosenborg Slot, now well within the city limits.
A large proportion of Copenhagen's historic sites can be found on the small 'museum island' of Slotsholmen, ringed by canals and connected to the Indre Byen by a total of nine bridges. Denmark's parliament, Christiansborg - and the original ruins of Absalon's castle beneath it - is located here, along with the magnificent Thorvaldsens Museum, Christiansborg Slotskirke and the Royal Riding Stables.
Out of the city, two castles are worth a visit: Kronborg Slot, the setting for Shakespeare's Hamlet, in Elsinore and Frederiksborg Slot and its surrounding baroque gardens, a stunning example of renaissance architecture and home to Denmark's Museum of Natural History.
Copenhagen's oldest surviving church is the German Sankt Petri Kirke, which dates back to the Middle Ages. The City Hall dates from 1905, and was inspired by a similar building in Siena, Italy. Finally, take a walk through the city's brewing heritage on the old Carlsberg grounds; with production having moved elsewhere, this is now open to the public as visitor center.