In 13 German states, the primary administrative subdivision higher than a Gemeinde (municipality) is the or . Most major cities in Germany are not part of any Kreis, but instead combine the functions of a municipality and a Kreis; such a city is referred to as a or . (Land-)Kreise stand at an intermediate level of administration between each state () and the municipalities () within it. These correspond to level-3 administrative units in the Nomenclature of Territorial Units for Statistics (NUTS 3). Previously, the similar title Imperial Circle () referred to groups of states in the Holy Roman Empire. The related term was used for similar administrative divisions in some German territories until the 19th century. Types of districts The majority of German districts are "rural districts" (German: ), of which there are 294 . Cities with more than 100,000 inhabitants (and smaller towns in some states) do not usually belong to a district, but take on district responsibilities themselves, similar to the concept of independent cities. These are known as "urban districts" (German: or )—cities which constitute a district in their own right—and there are 107 of them, bringing the total number of districts to 401. , approximately 26 million people live in these 107 urban districts. In North Rhine-Westphalia, there are some cities with more than 100,000 inhabitants which are not urban districts, these being Recklinghausen, Gütersloh, Siegen, Paderborn, Bergisch Gladbach, Neuss and Moers. Nevertheless, these cities take over many district responsibilities themselves, although they are still part of a larger rural district. Midsize towns can perform particular administrative functions of the district as well, especially to provide common services to the local citizens. The classification as "midsize" town is usually based on a town's registered population, but varies from state to state. A special type of rural districts includes the three (Municipal unions of special kind), a fusion of a district-free town with its adjacent rural district: besides the Regionalverband Saarbrücken (Saarbrücken regional association), from 1974 until 2007 called "Stadtverband Saarbrücken" (Saarbrücken town association), there is the Hanover Region since 2001 and the Städteregion Aachen (Aachen region of towns) since 2009. Aachen, Hanover and Göttingen retain certain rights of an urban district (Kreisfreie Stadt); Saarbrücken has not explicitly determined a similar provision in its legislation. Responsibilities According to common federal and state laws, the districts are responsible for the following tasks: The building and upkeep of