In North Rhine-Westphalia , there are some cities with more than 100,000 inhabitants which are not urban districts , for example Iserlohn , Recklinghausen , Siegen , Paderborn , Bergisch Gladbach , Witten and Neuss . In North Rhine-Westphalia , there are some cities with more than 100,000 inhabitants which are not urban districts , for example Recklinghausen , Siegen , Paderborn , Bergisch Gladbach , Neuss and Moers .