Picture from Wikimedia Commons, Bruno Jargot
Christiania is an anarchist, autonomous community. According to Wikipedia, the area has a unique status in that it is regulated by a special law, the Christiania Law of 1989 which transfers parts of the supervision of the area from the municipality of Copenhagen to the state. Many of the living rules, such as building permits, are decided by consensus in a general assembly of residents. The residents of Christiania do not live independent of the Danish state: they pay taxes, their children go to recognised schools, and if there is a fire, they do allow the fire brigade to enter the area, and residents are not necessarily opposed to the existance of the state (though the reverse of the sign in the picture reads You are now entering the EU).
In practice, what makes Christania special? What is the relation between Christania and the Danish government, local or national? What are the powers that have been granted to the community? How far does its independence go?
I'm looking for answers that summarise the special status of Christiania in a political-legal context, not so much in the culture of the residents. Christiania seems quite unique — but why?