It's a Scandinavian country famous for its fierce Viking past and being the birthplace of Lego, which has produced billions of coloured plastic pieces around the world - a statistic coming as no surprise to anyone who has stepped barefoot on a Lego piece in the middle of the night.
Copenhagen is a cosmopolitan city without the obstinate over-development and polluted modernity. For one thing they do not let cars dominate their public spaces unlike most other countries do. There's strict anti-pollution laws and a whopping tax is levied when buying a new car, which explains the large number of bicycles that make up street traffic. It is small enough to walk around and explore on foot, but large enough not to feel that you are visiting the same street over and over again.
Another great thing about Copenhagen is that everyone speaks English, although for their own amusement some Danes might ask you to pronounce the tongue twister "rød grød med fløde" (the name of a dessert). Danes are not as outgoing when it comes to talking to strangers and they usually dress like they're on their way to a funeral (ie in all black) but just under the surface they are actually friendly and funny, something they call hygge (which loosely translates as "humour & cozyness").