Areas known for their salt mines include Kilroot near Carrickfergus, Ireland (over 100 years old and more than 25 km of passages), Khewra in Pakistan, Tuzla in Bosnia, Wieliczka and Bochnia in Poland, Hallstatt and Salzkammergut in Austria, Rheinberg in Germany, Sl???nic in Romania, Provadiya in Bulgaria, Avery Island in Louisiana, United States, the wich towns of Cheshire and Worcestershire in England, and the Detroit Salt Company's 1,500-acre subterranean complex 1,100 feet beneath the city of Detroit. __