Karviná (Czech pronunciation: [ˈkarvɪnaː]; Polish: Karwina, Polish pronunciation: [karˈvina], German: Karwin) is a city in the Moravian-Silesian Region of the Czech Republic. It has about 50,000 inhabitants. It lies on the Olza River in the historical region of Cieszyn Silesia. Karviná is known as an industrial city with tradition in coal mining. The historic centre in Karviná-Fryštát is well preserved and is protected by law as an urban monument zone.