There are not many natural hills in Ostrava so the local residents had to build some themselves. One of them is the 315 metres above the sea high Ema Heap in Silesian Ostrava which consists of tonnes of waste rock, these days covered by birches. It is the only state protected heap in the Ostrava-Karviná Region. Thanks to the amazing view, the top of the heap is very popular among visitors. The interesting point is that the heap is still working. Clouds of smoke containing mainly methane and sulphur dioxide rise from the heap and the inner temperature reaches over 1000 °C. The trip to Ema Heap is allowed at the peoples’ own risk. The top can be reached following the tourist track from Silesian Ostrava Castle, Miloš Sýkora Bridge or from the Zoo.