Kladno is the largest city of the region, together with its adjacent suburban areas forming an agglomeration of more than 110,000 inhabitants, situated in the close vicinity of Prague. The first written evidence of Kladno dates back from the 14th century. Kladno was the historical birthplace of Bohemian heavy industries in the past. The mining industry began here in 1842.
Anton Cermak, later mayor of Chicago, Illinois, was born here (as Antonín Čermák) in 1873.