Pernik is a town located in western Bulgaria, situated within the Pernik Valley. It serves as the principal town of Pernik Province, a region neighboring the Serbian border. The town is positioned on both banks of the Struma River and is surrounded by several geographic landmarks, including the Golo Bardo, Vitosha, Lyulin, and Viskyar mountains.
As of 2021, Pernik has a population of 70,285. It holds the distinction of being the most populated town in western Bulgaria following the capital city of Sofia.