For self-governance purposes, the city is divided into 17 boroughs, each of which has its own mayor (''starosta'') and council. The number of councillors in each depends on the size and population of the borough. Each of the boroughs coincides with the city's 20 cadastral areas, except for two cases: Nové Mesto is further divided into the Nové Mesto and Vinohrady cadastral areas and Ružinov is divided into Ružinov, Nivy and Trnávka. Further unofficial division recognizes additional quarters and localities.