Farms, vineyards, orchards, and pastures for stock form the basis of S Slovakia's economy. The main crops are wheat, barley, potatoes, sugar beets, hops, and fruit. Pigs, cattle, and poultry are raised. The mountainous part of Slovakia has vast forests and pastures, used for intensive sheep grazing, and is rich in mineral resources, including coal, high-grade iron ore, copper, manganese, lead, and zinc. There are also numerous mineral springs, notably at Piešt'any, and many popular resorts. Slovakia has undergone considerable industrialization and urbanization since World War II. Its industries produce metals and metal products, foods and beverages, electricity, oil and gas, coke, nuclear fuel, chemicals, synthetic fibers, machinery, paper, ceramics, motor vehicles, textiles, electrical and optical instruments, and rubber products. Exports include vehicles, machinery, electrical equipment, metals, chemicals, minerals, and plastics. The main imports are machinery, transportation equipment, manufactured goods, fuels, and chemicals. Its main trading partners are Germany, the Czech Republic, Austria, Italy, and Poland.