The reserve is located on the territory of the St ęporków commune. Established in 1997, its main purpose was to protect the outcrops of lower Jurassic rocks containing important minerals, fossils and various forms of ironstone.
The reserve contains a former open pit mine of ceramic clay once used in the production of bricks. The name of the reserve is derived from the rare bituminous variety of lignite known as gagat. Due to its shining luster, gagat is used in the jewelry trade.