Visiting the active open pit coal mine "Drmno" where the lignite coal is exploited. Open coal mine “Drmno“ is the main source for Kostolac A and B thermal plants with total power of 1 000 MW. Sightseeing of the mine from observation point. It is possible to take a look at the whole lithological section of the upper Pontian series. Series itself was discovered in the depths of approx. 80 m and width of more than 3km. It is easy to observe the surface soil cover below which extends a series of gravels and sand as well as productive coal layer.