Tvarditsa
From Wikipedia, the free encyclopedia
Tvarditsa (Bulgarian: Твърдица) is a town in the Sliven Province, eastern Bulgaria. As of 2006 it has 5 778 inhabitants. The town is located in the southern slopes of Stara Planina. The area around is known as the Tvarditsa Coal Basin, the only place in the country where soft coal is mined.
