Germany's largest city is the Ruhr valley.
) Some cities are now part of a continuous urban landscape called urban agglomeration, conurbation, or megalopolis (exemplified by the BosWash corridor of the Northeastern United States
 (Historically, the qualifying factor was the presence of a cathedral, resulting in some very small cities such as Wells, with a population 12,000 as of 2018 and St Davids, with a population of 1,841 as of 2011

