Copenhagen began as Havnen (the harbor), with the seat of local government near what is now Gammeltorv, just off the main pedestrian thoroughfare Strøget. Much of what is now the northeastern section of the downtown area was once under water. The harbor was dotted with islands. Through the centuries, various kings filled in the shallow waters and joined the islands to the mainland of Zealand. During those years, the ramparts of the city were constructed and a system of moats and other water defenses were created. Most maps of the city still reveal the general plan of older defense measures.
Copenhagen grew up within and, eventually, beyond these fortified ramparts. Many of the main neighborhood districts are named after what were once the few points of entry to the city. What can confuse some visitors is that the districts are named after points on the compass, but do not lie in that direction in relation to the city center. For instance, Vesterport means "western bridge" (the bridge was the western entry to Copenhagen), while the district lies southwest of downtown.
Nowadays downtown Copenhagen (indicated by a KBH K in mailing addresses) is concentrated around Strøget, in an area containing lots of stores, cafés, restaurants, office buildings, and galleries, with residential properties on the upper floors. Just over a decade ago the center of town (including its northeastern subdistrict Sankt Annæ Kvarter) was the absolute center of all shopping, dining, and nightlife activity. It still is thriving, but some of the action has moved to neighboring districts.
A couple of centuries ago the districts of Vesterbro (KBH V), Nørrebro (KBH N), and Østerbro (KBH Ø) were once the outskirts of Copenhagen, named after the ports for entering the city. In the past decade nightlife and shops have moved into these districts to make them much sought-after spots to live and play. Halmtorv in Vesterbro was once a haunt for street walkers and other urchins, but has become an "in" and increasingly gentrified neighborhood in recent years. The area of Nørrebro closest to downtown was once the working-class area of the city, but now contains some of the hottest property in town after cafés and shops sprouted in the area. Østerbro was mostly a bourgeois bastion, but has turned into a center for young families with lots of opportunity for shopping and recreation.
The man-made island of Christianshavn (KBH K) was filled and raised between Copenhagen and Amager island by King Christian IV to bolster the city's defense installations. Many of the military fortifications can still be seen, such as the Holmen naval base, which has become a thriving spot for creative offices, nightlife, and new residential growth. To the south Amager Island (KBH S) is a main focus of development and expansion plans for the Copenhagen metropolitan region.
Regular mail addressed to Copenhagen should include the street name and number, postal code of the region, and a letter after Copenhagen to signify the neighborhood. For example, Wonderful Copenhagen's office is at Gammel Kongevej 1, DK-1610, Copenhagen V, Denmark. The "V" after Copenhagen stands for Vesterbro neighborhood, and DK-1610 is the country's zip or postal code.