Pernik is a town about 30 km from the capital of sofia and despite its gloomy heavy industry image it has been inhabited for over 6 thousand years during the new stone age and the nearby krakra fortress shows remains from this period and the laterhellenisticperiod 4th century pernik opensthe first coal mine in 1891 and its high quality ores quickly develop the town where the first light bulb and the first electric power generator in bulgaria are installed the coal is widelyyieldedfr