Smoking Hills, Northwest Territories China In China, the world's largest coal producer with an annual output around 2.5 billion tons, coal fires are a serious problem. It has been estimated that some 10–200 million tons of coal uselessly burn annually, and that the same amount again is made inaccessible to mining. Coal fires extend over a belt across the entire north China, whereby over one hundred major fire areas are listed, each of which contains many individual fire zones. They are concentrated in the provinces of Xinjiang, Inner Mongolia and Ningxia. Beside losses from burned and inaccessible coal, these fires contribute to air pollution and considerably increased levels of greenhouse gas emissions and have thereby become a problem which has gained international attention. Germany In Planitz, now a part of the city of Zwickau, a coal seam that had been burning since 1476 was only quenched in 1860. In Dudweiler, Saarland, a coal-seam fire ignited around 1668 and is still burning. This so-called Burning Mountain ("Brennender Berg") soon became a tourist attraction and was even visited by Johann Wolfgang von Goethe. Also well-known is the so-called Stinksteinwand (stinking stone wall) in Schwalbenthal on the eastern slope of the Hoher Meißner, where several seams caught fire centuries ago after lignite coal mining ceased; combustion gas continues to reach the surface. India In India, as of 2010, 68 fires were burning beneath a region of the Jharia coalfield in Dhanbad, Jharkhand. Mine fires started in this region in 1916 and are rapidly destroying the only source of prime coking coal in the country. Indonesia Coal and peat fires in Indonesia are often ignited by forest fires near deposits at the surface. It is difficult to determine when a forest fire is started by a coal-seam fire, or vice versa. The most common cause of forest fires and haze in Indonesia is intentional burning of forest to clear land for plantation crops of pulp wood, rubber and palm oil. No accurate count of coal-seam fires has been completed in Indonesia. Only a minuscule fraction of the country has been surveyed for coal fires. The best data available come from a study based on systematic, on-the-ground observation. In 1998, a total of 125 coal fires were located and mapped within a 2-kilometer strip either side of a 100-kilometer stretch of road north of Balikpapan to Samarinda in East Kalimantan, using hand-held Global Positioning System